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• High shmmax value in Redhat 6.3

  - by xpapad

  We are using Redhat 6.3 with 30G RAM to host our Postgres server. The (default) shmmax value is 68,719,476,736 In some forums I have read that having an shmmax value larger than the RAM causes extensive paging, but in the Redhat forums it warns against changing a kernel parameter that is already configured to a value larger than the minimum requirements for an environment. In ServerFault I've read that this probably has no impact. So is there any impact of having shmmax value RAM in a DB server, or the kernel understands this and handles it appropriately? Thanks

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• How to set shmall, shmmax, shmni, etc ... in general and for postgresql

  - by jpic

  I've used the documentation from PostgreSQL to set it for example this config: >>> cat /proc/meminfo MemTotal: 16345480 kB MemFree: 1770128 kB Buffers: 382184 kB Cached: 10432632 kB SwapCached: 0 kB Active: 9228324 kB Inactive: 4621264 kB Active(anon): 7019996 kB Inactive(anon): 548528 kB Active(file): 2208328 kB Inactive(file): 4072736 kB Unevictable: 0 kB Mlocked: 0 kB SwapTotal: 0 kB SwapFree: 0 kB Dirty: 3432 kB Writeback: 0 kB AnonPages: 3034588 kB Mapped: 4243720 kB Shmem: 4533752 kB Slab: 481728 kB SReclaimable: 440712 kB SUnreclaim: 41016 kB KernelStack: 1776 kB PageTables: 39208 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 8172740 kB Committed_AS: 14935216 kB VmallocTotal: 34359738367 kB VmallocUsed: 399340 kB VmallocChunk: 34359334908 kB HardwareCorrupted: 0 kB AnonHugePages: 456704 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 12288 kB DirectMap2M: 16680960 kB >>> ipcs -l ------ Shared Memory Limits -------- max number of segments = 4096 max seg size (kbytes) = 4316816 max total shared memory (kbytes) = 4316816 min seg size (bytes) = 1 ------ Semaphore Limits -------- max number of arrays = 128 max semaphores per array = 250 max semaphores system wide = 32000 max ops per semop call = 32 semaphore max value = 32767 ------ Messages Limits -------- max queues system wide = 31918 max size of message (bytes) = 8192 default max size of queue (bytes) = 16384 sysctl.conf extract: kernel.shmall = 1079204 kernel.shmmax = 4420419584 postgresql.conf non defaults: max_connections = 60 # (change requires restart) shared_buffers = 4GB # min 128kB work_mem = 4MB # min 64kB wal_sync_method = open_sync # the default is the first option checkpoint_segments = 16 # in logfile segments, min 1, 16MB each checkpoint_completion_target = 0.9 # checkpoint target duration, 0.0 - 1.0 effective_cache_size = 6GB Is this appropriate ? If not (or not necessarily), in which case would it be appropriate ? We did note nice performance improvements with this config, how would you improve it ? How should kernel memory management parameters be set ? Can anybody explain how to really set them from the ground up ?

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• On checking kernel parms HP-UX & Oracle 10.2

  - by [email protected]

  Hi,Just did this little script for a customer wanting to investigate if the kernel parameters of their HP-UX machines fits or not the Oracle 10.2 specifications ( looks like someone checked the "User Verified" at database installation time on some prerequisites)Just want to share ( its in Spanish)Hope it helps!--L Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} ### ### check_kernel_parms.sh ### ### ### ###    NAME ###      check_kernel_parms.sh ### ###    DESCRIPTION ###      Comprueba los parametros de kernel ### ###    NOTES ###     Valido para versiones de SO HP-UX y Oracle 10.2 ###     ### ###    MODIFIED   (MM/DD/YY) ###    lvelasco    05/20/10 - Creacion     V_DATE=`/usr/bin/date +%Y%m%d_%H%M%S` if [ "${1}" != 'sin_traza' ]; then   V_FICHERO_LOG=`dirname $0`/`basename $0`.${V_DATE}.log   exec 4>&1   tee ${V_FICHERO_LOG} >&4 |&   exec 1>&p 2>&1 fi   echo "${V_DATE}- check_params.sh *******************************************" echo "Comenzado ejecucion de chequeo de parametros de kernel en maquina `hostname`" echo "****************************************************************************"   UX_VERS=`uname -a | awk '{print $3}'` KCTUNE=/usr/sbin/kctune MEM_TOTAL_MB=`./check_mem` <-- This should return the physical mem of the machine on bytes MEM_TOTAL=$((MEM_TOTAL_MB*1024))     NPROC=$(${KCTUNE} | grep nproc | grep -v '(nproc' | grep -v *nproc | awk '{print $2}') if [ ${NPROC} -lt 4096 ] then        echo "[FAILED] Information: El parametro nproc con valor actual ${NPROC} debe tener una valor superior a 4096" else        echo "[OK] Information: El parametro nproc con valor actual ${NPROC} debe tener una valor superior a 4096" fi     KSI_ALLOC_MAX_T=$(${KCTUNE} | grep ksi_alloc | awk '{print $2}') KSI_ALLOC_MAX=$((NPROC*8)) if [ ${KSI_ALLOC_MAX_T} -lt ${KSI_ALLOC_MAX} ] then        echo "[FAILED] Information: El parametro ksi_alloc_max con valor actual ${KSI_ALLOC_MAX_T} debe tener una valor superior a ${KSI_ALLOC_MAX}" else        echo "[OK] Information: El parametro ksi_alloc_max con valor actual ${KSI_ALLOC_MAX_T} debe tener una valor superior a ${KSI_ALLOC_MAX}" fi       EXECUTABLE_STACK=$(${KCTUNE} | grep executable_stack | awk '{print $2}') if [ ${EXECUTABLE_STACK} -ne 0 ] then        echo "[FAILED] Information: El parametro executable_stack con valor actual ${EXECUTABLE_STACK} debe tener una valor igual a 0" else        echo "[OK] Information: El parametro executable_stack con valor actual ${EXECUTABLE_STACK} debe tener una valor igual a 0" fi       MAX_THREAD_PROC=$(${KCTUNE} | grep max_thread_proc | awk '{print $2}') if [ ${MAX_THREAD_PROC} -lt 1024 ] then        echo "[FAILED] Information: El parametro max_thread_proc con valor actual ${MAX_THREAD_PROC} debe tener una valor superior a 1024" else        echo "[OK] Information: El parametro max_thread_proc con valor actual ${MAX_THREAD_PROC} debe tener una valor superior a 1024" fi     MAXDSIZ=$(${KCTUNE} | grep 'maxdsiz ' | awk '{print $2}') if [ ${MAXDSIZ} -lt 1073741824 ] then        echo "[FAILED] Information: El parametro maxdsiz con valor actual ${MAXDSIZ} debe tener una valor superior a 1073741824" else        echo "[OK] Information: El parametro maxdsiz con valor actual ${MAXDSIZ} debe tener una valor superior a 1073741824" fi     MAXDSIZ_64BIT=$(${KCTUNE} | grep maxdsiz_64bit | awk '{print $2}') if [ ${MAXDSIZ} -lt 2147483648 ] then        echo "[FAILED] Information: El parametro maxdsiz_64bit con valor actual ${MAXDSIZ_64BIT} debe tener una valor superior a 2147483648" else        echo "[OK] Information: El parametro maxdsiz_64bit con valor actual ${MAXDSIZ_64BIT} debe tener una valor superior a 2147483648" fi   MAXSSIZ=$(${KCTUNE} | grep 'maxssiz ' | awk '{print $2}') if [ ${MAXSSIZ} -lt 134217728 ] then        echo "[FAILED] Information: El parametro maxssiz con valor actual ${MAXSSIZ} debe tener una valor superior a 134217728" else        echo "[OK] Information: El parametro maxssiz con valor actual ${MAXSSIZ} debe tener una valor superior a 134217728" fi     MAXSSIZ_64BIT=$(${KCTUNE} | grep maxssiz_64bit | awk '{print $2}') if [ ${MAXSSIZ} -lt 1073741824 ] then        echo "[FAILED] Information: El parametro maxssiz_64bit con valor actual ${MAXSSIZ} debe tener una valor superior a 1073741824" else        echo "[OK] Information: El parametro maxssiz_64bit con valor actual ${MAXSSIZ} debe tener una valor superior a 1073741824" fi     MAXUPRC_T=$(${KCTUNE} | grep maxuprc | awk '{print $2}') MAXUPRC=$(((NPROC*9)/10)) if [ ${MAXUPRC_T} -lt ${MAXUPRC} ] then        echo "[FAILED] Information: El parametro maxuprc con valor actual ${MAXUPRC_T} debe tener una valor superior a ${MAXUPRC}" else        echo "[OK] Information: El parametro maxuprc con valor actual ${MAXUPRC_T} debe tener una valor superior a ${MAXUPRC}" fi   MSGMNI=$(${KCTUNE} | grep msgmni | awk '{print $2}') if [ ${MSGMNI} -lt ${NPROC} ] then        echo "[FAILED] Information: El parametro msgni con valor actual ${MSGMNI} debe tener una valor superior a ${NPROC}" else        echo "[OK] Information: El parametro msgni con valor actual ${MSGMNI} debe tener una valor superior a ${NPROC}" fi     if [ ${UX_VERS} = "B.11.23" ] then        MSGSEG=$(${KCTUNE} | grep msgseg | awk '{print $2}')        if [ ${MSGSEG} -lt 32767 ]        then        echo "[FAILED] Information: El parametro msgseg con valor actual ${MSGSEG} debe tener una valor superior a 32767"        else        echo "[OK] Information: El parametro msgseg con valor actual ${MSGSEG} debe tener una valor superior a 32767"        fi fi   MSGTQL=$(${KCTUNE} | grep msgtql | awk '{print $2}') if [ ${MSGTQL} -lt ${NPROC} ] then        echo "[FAILED] Information: El parametro msgtql con valor actual ${MSGTQL} debe tener una valor superior a ${NPROC}" else        echo "[OK] Information: El parametro msgtql con valor actual ${MSGTQL} debe tener una valor superior a ${NPROC}" fi       if [ ${UX_VERS} = "B.11.23" ] then        NFILE_T=$(${KCTUNE} | grep nfile | awk '{print $2}')        NFILE=$((15*NPROC+2048))        if [ ${NFILE_T} -lt ${NFILE} ]        then        echo "[FAILED] Information: El parametro nfile con valor actual ${NFILE_T} debe tener una valor superior a ${NFILE}"        else        echo "[OK] Information: El parametro nfile con valor actual ${NFILE_T} debe tener una valor superior a ${NFILE}"        fi fi     NFLOCKS=$(${KCTUNE} | grep nflocks | awk '{print $2}') if [ ${NFLOCKS} -lt ${NPROC} ] then        echo "[FAILED] Information: El parametro nflocks con valor actual ${NFLOCKS} debe tener una valor superior a ${NPROC}" else        echo "[OK] Information: El parametro nflocks con valor actual ${NFLOCKS} debe tener una valor superior a ${NPROC}" fi   NINODE_T=$(${KCTUNE} | grep ninode | grep -v vx | awk '{print $2}') NINODE=$((8*NPROC+2048)) if [ ${NINODE_T} -lt ${NINODE} ] then        echo "[FAILED] Information: El parametro ninode con valor actual ${NINODE_T} debe tener una valor superior a ${NINODE}" else        echo "[OK] Information: El parametro ninode con valor actual ${NINODE_T} debe tener una valor superior a ${NINODE}" fi     NCSIZE_T=$(${KCTUNE} | grep ncsize | awk '{print $2}') NCSIZE=$((NINODE+1024)) if [ ${NCSIZE_T} -lt ${NCSIZE} ] then        echo "[FAILED] Information: El parametro ncsize con valor actual ${NCSIZE_T} debe tener una valor superior a ${NCSIZE}" else        echo "[OK] Information: El parametro ncsize con valor actual ${NCSIZE_T} debe tener una valor superior a ${NCSIZE}" fi     if [ ${UX_VERS} = "B.11.23" ] then        MSGMAP_T=$(${KCTUNE} | grep msgmap | awk '{print $2}')        MSGMAP=$((MSGTQL+2))        if [ ${MSGMAP_T} -lt ${MSGMAP} ]        then        echo "[FAILED] Information: El parametro msgmap con valor actual ${MSGMAP_T} debe tener una valor superior a ${MSGMAP}"        else        echo "[OK] Information: El parametro msgmap con valor actual ${MSGMAP_T} debe tener una valor superior a ${MSGMAP}"        fi fi   NKTHREAD_T=$(${KCTUNE} | grep nkthread | awk '{print $2}') NKTHREAD=$((((NPROC*7)/4)+16)) if [ ${NKTHREAD_T} -lt ${NKTHREAD} ] then        echo "[FAILED] Information: El parametro nkthread con valor actual ${NKTHREAD_T} debe tener una valor superior a ${NKTHREAD}" else        echo "[OK] Information: El parametro nkthread con valor actual ${NKTHREAD_T} debe tener una valor superior a ${NKTHREAD}" fi     SEMMNI=$(${KCTUNE} | grep semmni | grep -v '(semm' | awk '{print $2}') if [ ${SEMMNI} -lt ${NPROC} ] then        echo "[FAILED] Information: El parametro semmni con valor actual ${SEMMNI} debe tener una valor superior a ${NPROC}" else        echo "[OK] Information: El parametro semmni con valor actual ${SEMMNI} debe tener una valor superior a ${NPROC}" fi     SEMMNS_T=$(${KCTUNE} | grep semmns | awk '{print $2}') SEMMNS=$((SEMMNI+2)) if [ ${SEMMNS_T} -lt ${SEMMNI} ] then        echo "[FAILED] Information: El parametro semmns con valor actual ${SEMMNS_T} debe tener una valor superior a ${SEMMNS}" else        echo "[OK] Information: El parametro semmns con valor actual ${SEMMNS_T} debe tener una valor superior a ${SEMMNS}" fi   SEMMNU_T=$(${KCTUNE} | grep semmnu | awk '{print $2}') SEMMNU=$((NPROC-4)) if [ ${SEMMNU_T} -lt ${SEMMNU} ] then        echo "[FAILED] Information: El parametro semmnu con valor actual ${SEMMNU_T} debe tener una valor superior a ${SEMMNU}" else        echo "[OK] Information: El parametro semmnu con valor actual ${SEMMNU_T} debe tener una valor superior a ${SEMMNU}" fi     if [ ${UX_VERS} = "B.11.23" ] then        SEMVMX=$(${KCTUNE} | grep msgseg | awk '{print $2}')        if [ ${SEMVMX} -lt 32767 ]        then        echo "[FAILED] Information: El parametro semvmx con valor actual ${SEMVMX} debe tener una valor superior a 32767"        else        echo "[OK] Information: El parametro semvmx con valor actual ${SEMVMX} debe tener una valor superior a 32767"        fi fi     SHMMNI=$(${KCTUNE} | grep shmmni | awk '{print $2}') if [ ${SHMMNI} -lt 512 ] then        echo "[FAILED] Information: El parametro shmmni con valor actual ${SHMMNI} debe tener una valor superior a 512" else        echo "[OK] Information: El parametro shmmni con valor actual ${SHMMNI} debe tener una valor superior a 512" fi     SHMSEG=$(${KCTUNE} | grep shmseg | awk '{print $2}') if [ ${SHMSEG} -lt 120 ] then        echo "[FAILED] Information: El parametro shmseg con valor actual ${SHMSEG} debe tener una valor superior a 120" else        echo "[OK] Information: El parametro shmseg con valor actual ${SHMSEG} debe tener una valor superior a 120" fi   VPS_CEILING=$(${KCTUNE} | grep vps_ceiling | awk '{print $2}') if [ ${VPS_CEILING} -lt 64 ] then        echo "[FAILED] Information: El parametro vps_ceiling con valor actual ${VPS_CEILING} debe tener una valor superior a 64" else        echo "[OK] Information: El parametro vps_ceiling con valor actual ${VPS_CEILING} debe tener una valor superior a 64" fi   SHMMAX=$(${KCTUNE} | grep shmmax | awk '{print $2}') if [ ${SHMMAX} -lt ${MEM_TOTAL} ] then         echo "[FAILED] Information: El parametro shmmax con valor actual ${SHMMAX} debe tener una valor superior a ${MEM_TOTAL}" else         echo "[OK] Information: El parametro shmmax con valor actual ${SHMMAX} debe tener una valor superior a ${MEM_TOTAL}" fi exit 0  

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• Avast Antivirus Crashes

  - by user67966

  Well I have installed avast anti virus on Ubuntu 12.04. But after updating, it crashes! So I have made some tweaks like below: 1) I pressed press Ctrl+Alt+T and opened Terminal. When it opened, I ran the command below. sudo gedit /etc/init.d/rcS 2) typed my password and hit enter 3) when the text file opens add the line: sysctl -w kernel.shmmax=128000000 4) made sure the line you added is before: exec /etc/init.d/rc S 5) This is how it should look like: Code: #! /bin/sh # rcS # # Call all S??* scripts in /etc/rcS.d/ in numerical/alphabetical order # sysctl -w kernel.shmmax=128000000 exec /etc/init.d/rc S 6) save it 7) Reboot My question is. Did I do anything wrong. I mean as I have made some tweaks,will it lower the security of avast down like viruses do! Please if you are a programmer check this if it contains bug or harmful intentions...Thanks.

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• Is this fix for Avast Antivirus crashing safe to use?

  - by TmRn

  Well I have installed avast anti virus on Ubuntu 12.04. But after updating, it crashes! So I have made some tweaks like below: Press Ctrl+Alt+T to open the Terminal. When it opens, run the command below. sudo gedit /etc/init.d/rcS Type your password and hit Enter. When the text file opens, add the line: sysctl -w kernel.shmmax=128000000 Make sure the line you added is before: exec /etc/init.d/rc S This is what it should look like: #! /bin/sh # rcS # # Call all S??* scripts in /etc/rcS.d/ in numerical/alphabetical order # sysctl -w kernel.shmmax=128000000 exec /etc/init.d/rc S Save the file. Reboot. My question is: Did I do anything wrong? I mean as I have made some tweaks, will it lower the security of Avast down like viruses do? Please if you are a programmer check this if it contains bug or harmful intentions... Thanks.

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• Setting kernel memory for installing postgresql

  - by Matthieu Taymans

  My question is about setting the kernel shared memory for installing postgresql on mac osx 10.6.8. In the readme file of postgresql it is said: Shared Memory PostgreSQL uses shared memory extensively for caching and inter-process communication. Unfortunately, the default configuration of Mac OS X does not allow suitable amounts of shared memory to be created to run the database server. Before running the installation, please ensure that your system is configured to allow the use of larger amounts of shared memory. Note that this does not 'reserve' any memory so it is safe to configure much higher values than you might initially need. You can do this by editting the file /etc/sysctl.conf - e.g. % sudo vi /etc/sysctl.conf On a MacBook Pro with 2GB of RAM, the author's sysctl.conf contains: kern.sysv.shmmax=1610612736 kern.sysv.shmall=393216 kern.sysv.shmmin=1 kern.sysv.shmmni=32 kern.sysv.shmseg=8 kern.maxprocperuid=512 kern.maxproc=2048 Note that (kern.sysv.shmall * 4096) should be greater than or equal to kern.sysv.shmmax. kern.sysv.shmmax must also be a multiple of 4096. Once you have edited (or created) the file, reboot before continuing with the installation. If you wish to check the settings currently being used by the kernel, you can use the sysctl utility: % sysctl -a The database server can now be installed. I'm a real beginner with all this but need to instal postgresql for academic purposes do you know how i can set this kernel shared memory. Won't that be harmful for my system? Thank you in advance. Matthieu

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• Installing Oracle 11gR2 on RHEL 6.2

  - by Chris

  Hello all I'm having some difficulty installing Oracle 11gR2 on RHEL 6.2 I have compiled a giant list of every single step I have taken so far I installed RHEL 6.2 on VMWARE it did it's easy install automatically I Selected 4gb of memory Selected max size of 80Gb Selected 2 processors Sorry for the bad styling copy paste isn't working correctly The version of oracle i downloaded is Linux x86-64 11.2.0.1 I am installing this on a local machine NOT a remote machine I followed the following documentation http://docs.oracle.com/cd/E11882_01/install.112/e24326/toc.htm I bolded the steps which I was least sure about from my research Easy installed with RHEL 6.2 for VMWARE Registered with red hat so I can get updates Reinstalled vmware-tools by pressing enter at every choice Sudo yum update at the end something about GPG key selected y then y Checked Memory Requirements grep MemTotal /proc/meminfo MemTotal: 3921368 kb uname -m x86_64 grep SwapTotal /proc/meminfo SwapTotal: 6160376 kb free total used free shared buffers cached Mem: 3921368 2032012 1889356 0 76216 1533268 -/+ buffers/cache: 422528 3498840 Swap: 6160376 0 6160376 df -h /dev/shm Filesystem Size Used Avail Use% Mounted on tmpfs 1.9G 276K 1.9G 1% /dev/shm df -h /tmp Filesystem Size Used Avail Use% Mounted on /dev/sda2 73G 2.7G 67G 4% / df -h Filesystem Size Used Avail Use% Mounted on /dev/sda2 73G 2.7G 67G 4% / tmpfs 1.9G 276K 1.9G 1% /dev/shm /dev/sda1 291M 58M 219M 21% /boot All looked fine to me except maybe for swap? Software Requirements cat /proc/version Linux version 2.6.32-220.el6.x86_64 ([email protected]) (gcc version 4.4.5 20110214 (Red Hat 4.4.5-6) (GCC) ) #1 SMP Wed Nov 9 08:03:13 EST 2011 uname -r 2.6.32-220.el6.x86_64 (same as above but whatever) According to the tutorial should be On Red Hat Enterprise Linux 6 2.6.32-71.el6.x86_64 or later These are the versions of software I have installed binutils-2.20.51.0.2-5.28.el6.x86_64 compat-libcap1-1.10-1.x86_64 compat-libstdc++-33-3.2.3-69.el6.x86_64 compat-libstdc++-33.i686 0:3.2.3-69.el6 gcc-4.4.6-3.el6.x86_64 gcc-c++.x86_64 0:4.4.6-3.el6 glibc-2.12-1.47.el6_2.12.x86_64 glibc-2.12-1.47.el6_2.12.i686 glibc-devel-2.12-1.47.el6_2.12.x86_64 glibc-devel.i686 0:2.12-1.47.el6_2.12 ksh.x86_64 0:20100621-12.el6_2.1 libgcc-4.4.6-3.el6.x86_64 libgcc-4.4.6-3.el6.i686 libstdc++-4.4.6-3.el6.x86_64 libstdc++.i686 0:4.4.6-3.el6 libstdc++-devel.i686 0:4.4.6-3.el6 libstdc++-devel-4.4.6-3.el6.x86_64 libaio-0.3.107-10.el6.x86_64 libaio-0.3.107-10.el6.i686 libaio-devel-0.3.107-10.el6.x86_64 libaio-devel-0.3.107-10.el6.i686 make-3.81-19.el6.x86_64 sysstat-9.0.4-18.el6.x86_64 unixODBC-2.2.14-11.el6.x86_64 unixODBC-devel-2.2.14-11.el6.x86_64 unixODBC-devel-2.2.14-11.el6.i686 unixODBC-2.2.14-11.el6.i686 8. Probably screwed up here or step 9 /usr/sbin/groupadd oinstall /usr/sbin/groupadd dba(not sure why this isn't in the tutorial) /usr/sbin/useradd -g oinstall -G dba oracle passwd oracle /sbin/sysctl -a | grep sem Xkernel.sem = 250 32000 32 128 /sbin/sysctl -a | grep shm kernel.shmmax = 68719476736 kernel.shmall = 4294967296 kernel.shmmni = 4096 vm.hugetlb_shm_group = 0 /sbin/sysctl -a | grep file-max Xfs.file-max = 384629 /sbin/sysctl -a | grep ip_local_port_range Xnet.ipv4.ip_local_port_range = 32768 61000 /sbin/sysctl -a | grep rmem_default Xnet.core.rmem_default = 124928 /sbin/sysctl -a | grep rmem_max Xnet.core.rmem_max = 131071 /sbin/sysctl -a | grep wmem_max Xnet.core.wmem_max = 131071 /sbin/sysctl -a | grep wmem_default Xnet.core.wmem_default = 124928 Here is my sysctl.conf file I only added the items that were bigger: Kernel sysctl configuration file for Red Hat Linux # For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and sysctl.conf(5) for more details. Controls IP packet forwarding net.ipv4.ip_forward = 0 Controls source route verification net.ipv4.conf.default.rp_filter = 1 Do not accept source routing net.ipv4.conf.default.accept_source_route = 0 Controls the System Request debugging functionality of the kernel kernel.sysrq = 0 Controls whether core dumps will append the PID to the core filename. Useful for debugging multi-threaded applications. kernel.core_uses_pid = 1 Controls the use of TCP syncookies net.ipv4.tcp_syncookies = 1 Disable netfilter on bridges. net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 Controls the maximum size of a message, in bytes kernel.msgmnb = 65536 Controls the default maxmimum size of a mesage queue kernel.msgmax = 65536 Controls the maximum shared segment size, in bytes kernel.shmmax = 68719476736 Controls the maximum number of shared memory segments, in pages kernel.shmall = 4294967296 fs.aio-max-nr = 1048576 fs.file-max = 6815744 kernel.sem = 250 32000 100 128 net.ipv4.ip_local_port_range = 9000 65500 net.core.rmem_default = 262144 net.core.rmem_max = 4194304 net.core.wmem_default = 262144 net.core.wmem_max = 1048576 /sbin/sysctl -p net.ipv4.ip_forward = 0 net.ipv4.conf.default.rp_filter = 1 net.ipv4.conf.default.accept_source_route = 0 kernel.sysrq = 0 kernel.core_uses_pid = 1 net.ipv4.tcp_syncookies = 1 error: "net.bridge.bridge-nf-call-ip6tables" is an unknown key error: "net.bridge.bridge-nf-call-iptables" is an unknown key error: "net.bridge.bridge-nf-call-arptables" is an unknown key kernel.msgmnb = 65536 kernel.msgmax = 65536 kernel.shmmax = 68719476736 kernel.shmall = 4294967296 fs.aio-max-nr = 1048576 fs.file-max = 6815744 kernel.sem = 250 32000 100 128 net.ipv4.ip_local_port_range = 9000 65500 net.core.rmem_default = 262144 net.core.rmem_max = 4194304 net.core.wmem_default = 262144 net.core.wmem_max = 1048576 su - oracle ulimit -Sn 1024 ulimit -Hn 1024 ulimit -Su 1024 ulimit -Hu 30482 ulimit -Su 1024 ulimit -Ss 10240 ulimit -Hs unlimited su - nano /etc/security/limits.conf *added to the end of the file * oracle soft nproc 2047 oracle hard nproc 16384 oracle soft nofile 1024 oracle hard nofile 65536 oracle soft stack 10240 exit exit su - mkdir -p /app/ chown -R oracle:oinstall /app/ chmod -R 775 /app/ 9. THIS IS PROBABLY WHERE I MESSED UP I then exited out of the root account so now I'm back in my account chris then I su - oracle echo $SHELL /bin/bash umask 0022 (so it should be set already to what is neccesary) Also from what I have read I do not need to set the DISPLAY variable because I'm installing this on the localhost I then opened the .bash_profile of the oracle and changed it to the following .bash_profile Get the aliases and functions if [ -f ~/.bashrc ]; then . ~/.bashrc fi User specific environment and startup programs PATH=$PATH:$HOME/bin; export PATH ORACLE_BASE=/app/oracle ORACLE_SID=orcl export ORACLE_BASE ORACLE_SID I then shutdown the virtual machine shared my desktop folder from my windows 7 then turned back on the virtual machine logged in as chris opened up a terminal then: su - for some reason the shared folder didn't appear so I reinstalled vmware tools again and restarted then same as before su - cp -R linux_oracle/database /db; chown -R oracle:oinstall /db; chmod -R 775 /db; ll /db drwxrwxr-x. 8 oracle oinstall 4096 Jun 5 06:20 database exit su - oracle cd /db/database ./runInstaller AND FINALLY THE INFAMOUS JAVA:132 ERROR MESSAGE Starting Oracle Universal Installer... Checking Temp space: must be greater than 80 MB. Actual 65646 MB Passed Checking swap space: must be greater than 150 MB. Actual 6015 MB Passed Checking monitor: must be configured to display at least 256 colors. Actual 16777216 Passed Preparing to launch Oracle Universal Installer from /tmp/OraInstall2012-06-05_06-47-12AM. Please wait ...[oracle@localhost database]$ Exception in thread "main" java.lang.UnsatisfiedLinkError: /tmp/OraInstall2012-06-05_06-47-12AM/jdk/jre/lib/i386/xawt/libmawt.so: libXext.so.6: cannot open shared object file: No such file or directory at java.lang.ClassLoader$NativeLibrary.load(Native Method) at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1751) at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1647) at java.lang.Runtime.load0(Runtime.java:769) at java.lang.System.load(System.java:968) at java.lang.ClassLoader$NativeLibrary.load(Native Method) at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1751) at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1668) at java.lang.Runtime.loadLibrary0(Runtime.java:822) at java.lang.System.loadLibrary(System.java:993) at sun.security.action.LoadLibraryAction.run(LoadLibraryAction.java:50) at java.security.AccessController.doPrivileged(Native Method) at java.awt.Toolkit.loadLibraries(Toolkit.java:1509) at java.awt.Toolkit.(Toolkit.java:1530) at com.jgoodies.looks.LookUtils.isLowResolution(Unknown Source) at com.jgoodies.looks.LookUtils.(Unknown Source) at com.jgoodies.looks.plastic.PlasticLookAndFeel.(PlasticLookAndFeel.java:122) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:242) at javax.swing.SwingUtilities.loadSystemClass(SwingUtilities.java:1783) at javax.swing.UIManager.setLookAndFeel(UIManager.java:480) at oracle.install.commons.util.Application.startup(Application.java:758) at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:164) at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:181) at oracle.install.commons.base.driver.common.Installer.startup(Installer.java:265) at oracle.install.ivw.db.driver.DBInstaller.startup(DBInstaller.java:114) at oracle.install.ivw.db.driver.DBInstaller.main(DBInstaller.java:132)

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• APC + FPM memory fragmentation without a reason

  - by palmic

  My setup @ debian 6-testing is: nginx 1.1.8 + php 5.3.8 + php-fpm + APC 3.1.9 Because i use automatic deployment with apc_clear_cache() after deploy, my target is to set up APC to cache all my project (up to 612 php files smaller than 1MB) without files changes checking. My confs: FPM: pm.max_children = 25 pm.start_servers = 4 pm.min_spare_servers = 2 pm.max_spare_servers = 10 pm.max_requests = 500 APC: pc.enabled="1" apc.shm_segments = 1 apc.shm_size="64M" apc.num_files_hint = 640 apc.user_entries_hint = 0 apc.ttl="7200" apc.user_ttl="7200" apc.gc_ttl="600" apc.cache_by_default="1" apc.filters = "apc\.php$,apc_clear.php$" apc.canonicalize="0" apc.slam_defense="1" apc.localcache="1" apc.localcache.size="512M" apc.mmap_file_mask="/tmp/apc-php5.XXXXXX" apc.enable_cli="0" apc.max_file_size = 2M apc.write_lock="1" apc.localcache = 1 apc.localcache.size = 512 apc.report_autofilter="0" apc.include_once_override="0" apc.coredump_unmap="0" apc.stat="0" apc.stat_ctime="0" The problem is i have my APC memory fragmented into 5 pieces at 14,5MB loaded into memory which capacity is 64M. My system memory is 640MB, used about 270MB at most. The http responses lasts about 300ms - 5s. When i switch on apc.stat="1", the responses are about 50ms - 80ms which is quite good, but i cannot understand why is apc.stat="0" so much whorse. The APC diagnostic tool shows "1 Segment(s) with 64.0 MBytes (mmap memory, pthread mutex Locks locking)" in general cache information window so i hope i am right that it's mmap setup which allows tweaking APC shm onto upper values than shows system limit in /proc/sys/kernel/shmmax (my shows 33MB).

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• Hugepages not utilized by MySQL 5.0, CentOS 5

  - by TechZilla

  I've set up Hugepages, but i'm not seeing any of them reserved. Have I missed a step, or for some particular reason, is MySQL is unable to utilize the Hugepages? I have not created a mount of hugetlbfs, although from what I read, MySQL would not call pages in such a manner. If I'm wrong, please let me know, as that would be a trivial solution. Almost all my MySQL tables are using InnoDB. NOTE: I created a hugetlbfs, no change as expected. Is it possible that rebooting would rectify this situation? I would not want to go through the procedure, as this is high availability, but would do so if necessary. This is the configurations, which I believe are relevant. /etc/sysctl.conf ... ## Huge Pages vm.nr_hugepages = 4096 vm.hugetlb_shm_group = 27 ## SHM kernel.shmmax = 34359738368 kernel.shmall = 8589934592 ... /etc/security/limits.conf ... mysql soft nofile 12888 mysql hard nofile 51552 @mysql soft memlock unlimited @mysql hard memlock unlimited /etc/my.cnf [mysqld] large-pages ... grep Huge /proc/meminfo HugePages_Total: 4096 HugePages_Free: 4096 HugePages_Rsvd: 0 Hugepagesize: 2048 kB id mysql uid=27(mysql) gid=27(mysql) groups=27(mysql) context=root:system_r:unconfined_t:SystemLow-SystemHigh tail -6 /var/log/mysqld.log InnoDB: HugeTLB: Warning: Failed to allocate 1342193664 bytes. errno 12 InnoDB HugeTLB: Warning: Using conventional memory pool 120808 15:49:25 InnoDB: Started; log sequence number 0 1729804158 120808 15:49:25 [Note] /usr/libexec/mysqld: ready for connections. Version: '5.0.95' socket: '/var/lib/mysql/mysql.sock' port: 3306 Source distribution I would really appreciate any help, I'm completely out of ideas. If I missed any more relevant configs, or diagnostics, please comment and I'll add it to the question.

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• Preventing DDOS/SYN attacks (as far as possible)

  - by Godius

  Recently my CENTOS machine has been under many attacks. I run MRTG and the TCP connections graph shoots up like crazy when an attack is going on. It results in the machine becoming inaccessible. My MRTG graph: mrtg graph This is my current /etc/sysctl.conf config # Kernel sysctl configuration file for Red Hat Linux # # For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and # sysctl.conf(5) for more details. # Controls IP packet forwarding net.ipv4.ip_forward = 0 # Controls source route verification net.ipv4.conf.default.rp_filter = 1 # Do not accept source routing net.ipv4.conf.default.accept_source_route = 0 # Controls the System Request debugging functionality of the kernel kernel.sysrq = 1 # Controls whether core dumps will append the PID to the core filename # Useful for debugging multi-threaded applications kernel.core_uses_pid = 1 # Controls the use of TCP syncookies net.ipv4.tcp_syncookies = 1 # Controls the maximum size of a message, in bytes kernel.msgmnb = 65536 # Controls the default maxmimum size of a mesage queue kernel.msgmax = 65536 # Controls the maximum shared segment size, in bytes kernel.shmmax = 68719476736 # Controls the maximum number of shared memory segments, in pages kernel.shmall = 4294967296 net.ipv4.conf.all.rp_filter = 1 net.ipv4.tcp_syncookies = 1 net.ipv4.icmp_echo_ignore_broadcasts = 1 net.ipv4.conf.all.accept_redirects = 0 net.ipv6.conf.all.accept_redirects = 0 net.ipv4.conf.all.send_redirects = 0 net.ipv4.conf.all.accept_source_route = 0 net.ipv4.conf.all.rp_filter = 1 net.ipv4.tcp_max_syn_backlog = 1280 Futher more in my Iptables file (/etc/sysconfig/iptables ) I only have this setup # Generated by iptables-save v1.3.5 on Mon Feb 14 07:07:31 2011 *filter :INPUT ACCEPT [1139630:287215872] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [1222418:555508541] Together with the settings above, there are about 800 IP's blocked via the iptables file by lines like: -A INPUT -s 82.77.119.47 -j DROP These have all been added by my hoster, when Ive emailed them in the past about attacks. Im no expert, but im not sure if this is ideal. My question is, what are some good things to add to the iptables file and possibly other files which would make it harder for the attackers to attack my machine without closing out any non-attacking users. Thanks in advance!

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• Limited connections to Ubuntu 12.04 server

  - by Luis M. Valenzuela

  I'm having a weird problem with my server. The server is inside my network, connected to a 3com switch which is connected to the router that handles the internet connection. The main purpose of the server is to host a php application. What's happening is that user 1 to 15 in the private network have no problems connecting to the server, when user 16 tries to connect a time out comes out and is unable to connect to the server. It's not just to the php application, but to any service from the server. When the 15 users are using the application, the server doesn't even answer to ping. I haven't set any special limit in Apache's ini file or MySql and the firewall is being turned off because the server is only to give service to the internal network. Is there a parameter in any of the network's card conf. files that might me causing this ? Or should I suspect from the router's or switches configuration ? UPDATE. Tomorrow, I'm gonna do some test on the server modifying two kernel params in : /etc/sysctl.conf The settings are: net.core.somaxconn which has the limit on simultaneous network connections to the server and kernel.shmmax which controls the amount of memory the system can use for managing connections.

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• radvd is not assigning prefix

  - by Samik

  I'm currently trying to setup IPv6 address auto-configuration with router advertisement daemon (radvd) on a virtual machine running CentOS 6.5. But the eth0 interface is not obtaining that prefix. I've obtained the ULA prefix from here. Contents of /etc/sysctl.conf # Kernel sysctl configuration file for Red Hat Linux # # For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and # sysctl.conf(5) for more details. # Controls IP packet forwarding net.ipv4.ip_forward = 0 net.ipv6.conf.all.forwarding = 1 # Controls source route verification net.ipv4.conf.default.rp_filter = 1 # Do not accept source routing net.ipv4.conf.default.accept_source_route = 0 # Controls the System Request debugging functionality of the kernel kernel.sysrq = 0 # Controls whether core dumps will append the PID to the core filename. # Useful for debugging multi-threaded applications. kernel.core_uses_pid = 1 # Controls the use of TCP syncookies net.ipv4.tcp_syncookies = 1 # Disable netfilter on bridges. net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 # Controls the default maxmimum size of a mesage queue kernel.msgmnb = 65536 # Controls the maximum size of a message, in bytes kernel.msgmax = 65536 # Controls the maximum shared segment size, in bytes kernel.shmmax = 68719476736 # Controls the maximum number of shared memory segments, in pages kernel.shmall = 4294967296 Contents of /etc/radvd.conf # NOTE: there is no such thing as a working "by-default" configuration file. # At least the prefix needs to be specified. Please consult the radvd.conf(5) # man page and/or /usr/share/doc/radvd-*/radvd.conf.example for help. # # interface eth0 { AdvSendAdvert on; MinRtrAdvInterval 3; MaxRtrAdvInterval 10; AdvDefaultPreference low; AdvHomeAgentFlag off; prefix fd8a:8d9d:808f:1::/64 { AdvOnLink on; AdvAutonomous on; AdvRouterAddr on; }; }; Contents of /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 HWADDR=52:54:00:74:d7:46 TYPE=Ethernet UUID=af5db1cb-e809-4098-be1a-5a74dbb767b1 ONBOOT=yes NM_CONTROLLED=no BOOTPROTO=dhcp IPV6INIT=yes IPV6_AUTOCONF=yes I've also enabled radvd at startup through chkconfig. Though I noticed that radvd is starting after interfaces are brought up. I've tried restarting the network service afterwards but still I get the following link-local address only #ip -6 addr show 1: lo: mtu 16436 inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: mtu 1500 qlen 1000 inet6 fe80::5054:ff:fe74:d746/64 scope link valid_lft forever preferred_lft forever Edit: Based on the answer given by Sander Steffann I still need clarification on some points but I'm posting here what worked. Contents of /etc/sysconfig/network NETWORKING=yes HOSTNAME=syslog-ng-server NETWORKING_IPV6=yes IPV6FORWARDING=yes Contents of /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 HWADDR=52:54:00:74:d7:46 TYPE=Ethernet UUID=af5db1cb-e809-4098-be1a-5a74dbb767b1 ONBOOT=yes NM_CONTROLLED=no BOOTPROTO=dhcp IPV6INIT=yes IPV6_AUTOCONF=yes IPV6FORWARDING=no Removed following line from /etc/sysctl.conf net.ipv6.conf.all.forwarding = 1 Contents of /etc/radvd.conf is as previous.

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• Proxy / Squid 2.7 / Debian Wheezy 6.7 / lots of TCP Timed-out

  - by Maroon Ibrahim

  i'm facing a lot of TCP timed-out on a busy cache server and here below my sysctl.conf configuration as well as an output of "netstat -st" Kernel 3.2.0-4-amd64 #1 SMP Debian 3.2.57-3 x86_64 GNU/Linux Any advice or help would be highly appreciated #################### Sysctl.conf cat /etc/sysctl.conf net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_tw_recycle = 1 fs.file-max = 65536 net.ipv4.tcp_low_latency = 1 net.core.wmem_max = 8388608 net.core.rmem_max = 8388608 net.ipv4.ip_local_port_range = 1024 65000 fs.aio-max-nr = 131072 net.ipv4.tcp_fin_timeout = 10 net.ipv4.tcp_keepalive_time = 60 net.ipv4.tcp_keepalive_intvl = 10 net.ipv4.tcp_keepalive_probes = 3 kernel.threads-max = 131072 kernel.msgmax = 32768 kernel.msgmni = 64 kernel.msgmnb = 65536 kernel.shmmax = 68719476736 kernel.shmall = 4294967296 net.ipv4.ip_forward = 1 net.ipv4.tcp_timestamps = 0 net.ipv4.conf.all.accept_redirects = 0 net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_sack = 0 net.ipv4.tcp_syncookies = 1 net.ipv4.ip_dynaddr = 1 vm.swappiness = 0 vm.drop_caches = 3 net.ipv4.tcp_moderate_rcvbuf = 1 net.ipv4.tcp_no_metrics_save = 1 net.ipv4.tcp_ecn = 0 net.ipv4.tcp_max_orphans = 131072 net.ipv4.tcp_orphan_retries = 1 net.ipv4.conf.default.rp_filter = 0 net.ipv4.conf.default.accept_source_route = 0 net.ipv4.tcp_max_syn_backlog = 32768 net.core.netdev_max_backlog = 131072 net.ipv4.tcp_mem = 6085248 16227328 67108864 net.ipv4.tcp_wmem = 4096 131072 33554432 net.ipv4.tcp_rmem = 4096 174760 33554432 net.core.rmem_default = 33554432 net.core.rmem_max = 33554432 net.core.wmem_default = 33554432 net.core.wmem_max = 33554432 net.core.somaxconn = 10000 # ################ Netstat results /# netstat -st IcmpMsg: InType0: 2 InType3: 233754 InType8: 56251 InType11: 23192 OutType0: 56251 OutType3: 437 OutType8: 4 Tcp: 20680741 active connections openings 63642431 passive connection openings 1126690 failed connection attempts 2093143 connection resets received 13059 connections established 2649651696 segments received 2195445642 segments send out 183401499 segments retransmited 38299 bad segments received. 14648899 resets sent UdpLite: TcpExt: 507 SYN cookies sent 178 SYN cookies received 1376771 invalid SYN cookies received 1014577 resets received for embryonic SYN_RECV sockets 4530970 packets pruned from receive queue because of socket buffer overrun 7233 packets pruned from receive queue 688 packets dropped from out-of-order queue because of socket buffer overrun 12445 ICMP packets dropped because they were out-of-window 446 ICMP packets dropped because socket was locked 33812202 TCP sockets finished time wait in fast timer 622 TCP sockets finished time wait in slow timer 573656 packets rejects in established connections because of timestamp 133357718 delayed acks sent 23593 delayed acks further delayed because of locked socket Quick ack mode was activated 21288857 times 839 times the listen queue of a socket overflowed 839 SYNs to LISTEN sockets dropped 41 packets directly queued to recvmsg prequeue. 79166 bytes directly in process context from backlog 24 bytes directly received in process context from prequeue 2713742130 packet headers predicted 84 packets header predicted and directly queued to user 1925423249 acknowledgments not containing data payload received 877898013 predicted acknowledgments 16449673 times recovered from packet loss due to fast retransmit 17687820 times recovered from packet loss by selective acknowledgements 5047 bad SACK blocks received Detected reordering 11 times using FACK Detected reordering 1778091 times using SACK Detected reordering 97955 times using reno fast retransmit Detected reordering 280414 times using time stamp 839369 congestion windows fully recovered without slow start 4173098 congestion windows partially recovered using Hoe heuristic 305254 congestion windows recovered without slow start by DSACK 933682 congestion windows recovered without slow start after partial ack 77828 TCP data loss events TCPLostRetransmit: 5066 2618430 timeouts after reno fast retransmit 2927294 timeouts after SACK recovery 3059394 timeouts in loss state 75953830 fast retransmits 11929429 forward retransmits 51963833 retransmits in slow start 19418337 other TCP timeouts 2330398 classic Reno fast retransmits failed 2177787 SACK retransmits failed 742371590 packets collapsed in receive queue due to low socket buffer 13595689 DSACKs sent for old packets 50523 DSACKs sent for out of order packets 4658236 DSACKs received 175441 DSACKs for out of order packets received 880664 connections reset due to unexpected data 346356 connections reset due to early user close 2364841 connections aborted due to timeout TCPSACKDiscard: 1590 TCPDSACKIgnoredOld: 241849 TCPDSACKIgnoredNoUndo: 1636687 TCPSpuriousRTOs: 766073 TCPSackShifted: 74562088 TCPSackMerged: 169015212 TCPSackShiftFallback: 78391303 TCPBacklogDrop: 29 TCPReqQFullDoCookies: 507 TCPChallengeACK: 424921 TCPSYNChallenge: 170388 IpExt: InBcastPkts: 351510 InOctets: -609466797 OutOctets: -1057794685 InBcastOctets: 75631402 #

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• Windows 2008 running as KVM guest networking issue

  - by Evolver

  I have a strange networking problem with Windows 2008 server R2, running as guest under KVM-Qemu host. Host is CentOS 6.3 x86_64. It's network settings: # cat /etc/sysconfig/network-scripts/ifcfg-br0 DEVICE=br0 BOOTPROTO=static BROADCAST=xx.xx.xx.63 IPADDR=xx.xx.xx.4 NETMASK=255.255.255.192 NETWORK=xx.xx.xx.0 ONBOOT=yes TYPE=Bridge # cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 HWADDR=xx:xx:xx:xx:xx:xx ONBOOT=yes BRIDGE=br0 IPV6INIT=yes IPV6_AUTOCONF=yes # cat /etc/sysconfig/network NETWORKING=yes NETWORKING_IPV6=no HOSTNAME=my.hostname GATEWAY=xx.xx.xx.1 # cat /etc/sysctl net.ipv4.ip_forward = 1 # tried to set it to 0 without any changes net.ipv4.conf.default.rp_filter = 1 # tried to set it to 0 without any changes net.ipv4.conf.default.accept_source_route = 0 # tried to set it to 1 without any changes kernel.sysrq = 0 kernel.core_uses_pid = 1 net.ipv4.tcp_syncookies = 1 net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 kernel.msgmnb = 65536 kernel.msgmax = 65536 kernel.shmmax = 68719476736 kernel.shmall = 4294967296 # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface xx.xx.xx.0 0.0.0.0 255.255.255.192 U 0 0 0 br0 169.254.0.0 0.0.0.0 255.255.0.0 U 1004 0 0 br0 0.0.0.0 xx.xx.xx.1 0.0.0.0 UG 0 0 0 br0 Node IP is xx.xx.xx.4, guest IP is xx.xx.xx.24, both host and guest is in the same network (/26). There are several linux guest running fine on the node (centos, debian, ubuntu, arch), and even Windows 2003 x86 also running fine. But Win2008 does not. I wonder, what's the difference. From Win2008 guest I can ping nothing: neither gateway, nor any other IP, even they are in the same subnet. From outside I also cannot ping guest. Almost. If I ping it from another server in same subnet, it's barely pinging, losing more than 90% packets. Firewall on the guest is completely off. Tried to set up network manually as well as via DHCP without success (BTW, DHCP set up network settings correctly). I suspect that is a kind of routing problem, but I spent whole day and still cannot figure it out. I would be appreciate for any help.

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• APC PHP cache size does not exceed 32MB, even though settings allow for more

  - by hardy101

  I am setting up APC (v 3.1.9) on a high-traffic WordPress installation on CentOS 6.0 64 bit. I have figured out many of the quirks with APC, but something is still not quite right. No matter what settings I change, APC never actually caches more than 32MB. I'm trying to bump it up to 256 MB. 32MB is a default amount for apc.shm_size, so I am wondering if it's stuck there somehow. I have run the following echo '2147483648' > /proc/sys/kernel/shmmax to increase my system's shared memory to 2G (half of my 4G box). Then ran ipcs -lm which returns ------ Shared Memory Limits -------- max number of segments = 4096 max seg size (kbytes) = 2097152 max total shared memory (kbytes) = 8388608 min seg size (bytes) = 1 Also made a change in /etc/sysctl.conf then ran sysctl -p to make the settings stick on the server. Rebooted, too, for good measure. In my APC settings, I have mmap enabled (which happens by default in recent versions of APC). php.ini looks like: apc.stat=0 apc.shm_size="256M" apc.max_file_size="10M" apc.mmap_file_mask="/tmp/apc.XXXXXX" apc.ttl="7200" I am aware that mmap mode will ignore references to apc.shm_segments, so I have left it out with default 1. phpinfo() indicates the following about APC: Version 3.1.9 APC Debugging Disabled MMAP Support Enabled MMAP File Mask /tmp/apc.bPS7rB Locking type pthread mutex Locks Serialization Support php Revision $Revision: 308812 $ Build Date Oct 11 2011 22:55:02 Directive Local Value apc.cache_by_default On apc.canonicalize O apc.coredump_unmap Off apc.enable_cli Off apc.enabled On On apc.file_md5 Off apc.file_update_protection 2 apc.filters no value apc.gc_ttl 3600 apc.include_once_override Off apc.lazy_classes Off apc.lazy_functions Off apc.max_file_size 10M apc.mmap_file_mask /tmp/apc.bPS7rB apc.num_files_hint 1000 apc.preload_path no value apc.report_autofilter Off apc.rfc1867 Off apc.rfc1867_freq 0 apc.rfc1867_name APC_UPLOAD_PROGRESS apc.rfc1867_prefix upload_ apc.rfc1867_ttl 3600 apc.serializer default apc.shm_segments 1 apc.shm_size 256M apc.slam_defense On apc.stat Off apc.stat_ctime Off apc.ttl 7200 apc.use_request_time On apc.user_entries_hint 4096 apc.user_ttl 0 apc.write_lock On apc.php reveals the following graph, no matter how long the server runs (cache size fluctuates and hovers at just under 32MB. See image http://i.stack.imgur.com/2bwMa.png You can see that the cache is trying to allocate 256MB, but the brown piece of the pie keeps getting recycled at 32MB. This is confirmed as refreshing the apc.php page shows cached file counts that move up and down (implying that the cache is not holding onto all of its files). Does anyone have an idea of how to get APC to use more than 32 MB for its cache size?? **Note that the identical behavior occurs for eaccelerator, xcache, and APC. I read here: http://www.litespeedtech.com/support/forum/archive/index.php/t-5072.html that suEXEC could cause this problem.

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• Scan a Windows PC for Viruses from a Ubuntu Live CD

  - by Trevor Bekolay

  Getting a virus is bad. Getting a virus that causes your computer to crash when you reboot is even worse. We’ll show you how to clean viruses from your computer even if you can’t boot into Windows by using a virus scanner in a Ubuntu Live CD. There are a number of virus scanners available for Ubuntu, but we’ve found that avast! is the best choice, with great detection rates and usability. Unfortunately, avast! does not have a proper 64-bit version, and forcing the install does not work properly. If you want to use avast! to scan for viruses, then ensure that you have a 32-bit Ubuntu Live CD. If you currently have a 64-bit Ubuntu Live CD on a bootable flash drive, it does not take long to wipe your flash drive and go through our guide again and select normal (32-bit) Ubuntu 9.10 instead of the x64 edition. For the purposes of fixing your Windows installation, the 64-bit Live CD will not provide any benefits. Once Ubuntu 9.10 boots up, open up Firefox by clicking on its icon in the top panel. Navigate to http://www.avast.com/linux-home-edition. Click on the Download tab, and then click on the link to download the DEB package. Save it to the default location. While avast! is downloading, click on the link to the registration form on the download page. Fill in the registration form if you do not already have a trial license for avast!. By the time you’ve filled out the registration form, avast! will hopefully be finished downloading. Open a terminal window by clicking on Applications in the top-left corner of the screen, then expanding the Accessories menu and clicking on Terminal. In the terminal window, type in the following commands, pressing enter after each line. cd Downloadssudo dpkg –i avast* This will install avast! on the live Ubuntu environment. To ensure that you can use the latest virus database, while still in the terminal window, type in the following command: sudo sysctl –w kernel.shmmax=128000000 Now we’re ready to open avast!. Click on Applications on the top-left corner of the screen, expand the Accessories folder, and click on the new avast! Antivirus item. You will first be greeted with a window that asks for your license key. Hopefully you’ve received it in your email by now; open the email that avast! sends you, copy the license key, and paste it in the Registration window. avast! Antivirus will open. You’ll notice that the virus database is outdated. Click on the Update database button and avast! will start downloading the latest virus database. To scan your Windows hard drive, you will need to “mount” it. While the virus database is downloading, click on Places on the top-left of your screen, and click on your Windows hard drive, if you can tell which one it is by its size. If you can’t tell which is the correct hard drive, then click on Computer and check out each hard drive until you find the right one. When you find it, make a note of the drive’s label, which appears in the menu bar of the file browser. Also note that your hard drive will now appear on your desktop. By now, your virus database should be updated. At the time this article was written, the most recent version was 100404-0. In the main avast! window, click on the radio button next to Selected folders and then click on the “+” button to the right of the list box. It will open up a dialog box to browse to a location. To find your Windows hard drive, click on the “>” next to the computer icon. In the expanded list, find the folder labelled “media” and click on the “>” next to it to expand it. In this list, you should be able to find the label that corresponds to your Windows hard drive. If you want to scan a certain folder, then you can go further into this hierarchy and select that folder. However, we will scan the entire hard drive, so we’ll just press OK. Click on Start scan and avast! will start scanning your hard drive. If a virus is found, you’ll be prompted to select an action. If you know that the file is a virus, then you can Delete it, but there is the possibility of false positives, so you can also choose Move to chest to quarantine it. When avast! is done scanning, it will summarize what it found on your hard drive. You can take different actions on those files at this time by right-clicking on them and selecting the appropriate action. When you’re done, click Close. Your Windows PC is now free of viruses, in the eyes of avast!. Reboot your computer and with any luck it will now boot up! Alternatives to avast! If avast! and a liberal amount of Googling doesn’t fix your problem, it’s possible that a different virus scanner will fix your obscure issue. Here are a list of other virus scanners available for Ubuntu that are either free or offer free trials. See their support forums for help on installing these virus scanners. Avira AntiVir Personal for Linux / Solaris Panda Antivirus for Linux Installation and usage guide from Ubuntu F-PROT Antivirus for Linux ClamAV installation and usage guide from Ubuntu NOD32 Antivirus for Linux Kaspersky Anti-Virus 2010 Bitdefender Antivirus for Unices Conclusion Running avast! from a Ubuntu Live CD can clean the vast majority of viruses from your Windows PC. This is another reason to always have a Ubuntu Live CD ready just in case something happens to your Windows installation! Similar Articles Productive Geek Tips Secure Computing: Windows Live OneCareHow To Remove Antivirus Live and Other Rogue/Fake Antivirus MalwareUse the Windows Key for the "Start" Menu in Ubuntu LinuxScan Files for Viruses Before You Download With Dr.WebAsk the Readers: Share Your Tips for Defeating Viruses and Malware TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 The Ultimate Guide For YouTube Lovers Will it Blend? iPad Edition Penolo Lets You Share Sketches On Twitter Visit Woolyss.com for Old School Games, Music and Videos Add a Custom Title in IE using Spybot or Spyware Blaster When You Need to Hail a Taxi in NYC

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• FreeBSD performance tuning. Sysctls, loader.conf, kernel.

  - by SaveTheRbtz

  I wanted to share knowledge of tuning FreeBSD via sysctls, so i'm posting them with comments. Based on Igor Sysoev (author of nginx) presentation about FreeBSD tuning up to 100,000-200,000 active connections. Sysctls are for 7.x FreeBSD. Since 7.2 amd64 some of them are tuned well by default. Prior 7.0 some of them are boot only (set via /boot/loader.conf) or does not exist at all. Highload web server sysctls: # Max. backlog size kern.ipc.somaxconn=4096 # Shared memory // 7.2+ can use shared memory > 2Gb kern.ipc.shmmax=2147483648 # Sockets kern.ipc.maxsockets=204800 # Do not use lager sockbufs on 8.0 # ( http://old.nabble.com/Significant-performance-regression-for-increased-maxsockbuf-on-8.0-RELEASE-tt26745981.html#a26745981 ) kern.ipc.maxsockbuf=262144 # Recive clusters (on amd64 7.2+ 65k is default) # For such high value vm.kmem_size must be increased to 3G #kern.ipc.nmbclusters=229376 # Jumbo pagesize(4k/8k) clusters # Used as general packet storage for jumbo frames # can be monitored via `netstat -m` #kern.ipc.nmbjumbop=192000 # Jumbo 9k/16k clusters # If you are using them #kern.ipc.nmbjumbo9=24000 #kern.ipc.nmbjumbo16=10240 # Every socket is a file, so increase them kern.maxfiles=204800 kern.maxfilesperproc=200000 kern.maxvnodes=200000 # Turn off receive autotuning #net.inet.tcp.recvbuf_auto=0 # Small receive space, only usable on http-server, on file server this # should be increased to 65535 or even more #net.inet.tcp.recvspace=8192 # Small send space is useful for http servers that serve small files # Autotuned since 7.x net.inet.tcp.sendspace=16384 # This should be enabled if you going to use big spaces (>64k) #net.inet.tcp.rfc1323=1 # Turn this off on highspeed, lossless connections (LAN 1Gbit+) #net.inet.tcp.delayed_ack=0 # This feature is useful if you are serving data over modems, Gigabit Ethernet, # or even high speed WAN links (or any other link with a high bandwidth delay product), # especially if you are also using window scaling or have configured a large send window. # You can try setting it to 0 on fileserver with 1GBit+ interfaces # Automatically disables on small RTT ( http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_subr.c?#rev1.237 ) #net.inet.tcp.inflight.enable=0 # Disable randomizing of ports to avoid false RST # Before usage check SA here www.bsdcan.org/2006/papers/ImprovingTCPIP.pdf # (it's also says that port randomization auto-disables at some conn.rates, but I didn't tested it thou) #net.inet.ip.portrange.randomized=0 # Increase portrange # For outgoing connections only. Good for seed-boxes and ftp servers. net.inet.ip.portrange.first=1024 net.inet.ip.portrange.last=65535 # Security net.inet.ip.redirect=0 net.inet.ip.sourceroute=0 net.inet.ip.accept_sourceroute=0 net.inet.icmp.maskrepl=0 net.inet.icmp.log_redirect=0 net.inet.icmp.drop_redirect=1 net.inet.tcp.drop_synfin=1 # Security net.inet.udp.blackhole=1 net.inet.tcp.blackhole=2 # Increases default TTL, sometimes useful # Default is 64 net.inet.ip.ttl=128 # Lessen max segment life to conserve resources # ACK waiting time in miliseconds (default: 30000 from RFC) net.inet.tcp.msl=5000 # Max bumber of timewait sockets net.inet.tcp.maxtcptw=40960 # Don't use tw on local connections # As of 15 Apr 2009. Igor Sysoev says that nolocaltimewait has some buggy realization. # So disable it or now till get fixed #net.inet.tcp.nolocaltimewait=1 # FIN_WAIT_2 state fast recycle net.inet.tcp.fast_finwait2_recycle=1 # Time before tcp keepalive probe is sent # default is 2 hours (7200000) #net.inet.tcp.keepidle=60000 # Should be increased until net.inet.ip.intr_queue_drops is zero net.inet.ip.intr_queue_maxlen=4096 # Interrupt handling via multiple CPU, but with context switch. # You can play with it. Default is 1; #net.isr.direct=0 # This is for routers only #net.inet.ip.forwarding=1 #net.inet.ip.fastforwarding=1 # This speed ups dummynet when channel isn't saturated net.inet.ip.dummynet.io_fast=1 # Increase dummynet(4) hash #net.inet.ip.dummynet.hash_size=2048 #net.inet.ip.dummynet.max_chain_len # Should be increased when you have A LOT of files on server # (Increase until vfs.ufs.dirhash_mem becames lower) vfs.ufs.dirhash_maxmem=67108864 # Explicit Congestion Notification (see http://en.wikipedia.org/wiki/Explicit_Congestion_Notification) net.inet.tcp.ecn.enable=1 # Flowtable - flow caching mechanism # Useful for routers #net.inet.flowtable.enable=1 #net.inet.flowtable.nmbflows=65535 # Extreme polling tuning #kern.polling.burst_max=1000 #kern.polling.each_burst=1000 #kern.polling.reg_frac=100 #kern.polling.user_frac=1 #kern.polling.idle_poll=0 # IPFW dynamic rules and timeouts tuning # Increase dyn_buckets till net.inet.ip.fw.curr_dyn_buckets is lower net.inet.ip.fw.dyn_buckets=65536 net.inet.ip.fw.dyn_max=65536 net.inet.ip.fw.dyn_ack_lifetime=120 net.inet.ip.fw.dyn_syn_lifetime=10 net.inet.ip.fw.dyn_fin_lifetime=2 net.inet.ip.fw.dyn_short_lifetime=10 # Make packets pass firewall only once when using dummynet # i.e. packets going thru pipe are passing out from firewall with accept #net.inet.ip.fw.one_pass=1 # shm_use_phys Wires all shared pages, making them unswappable # Use this to lessen Virtual Memory Manager's work when using Shared Mem. # Useful for databases #kern.ipc.shm_use_phys=1 /boot/loader.conf: # Accept filters for data, http and DNS requests # Usefull when your software uses select() instead of kevent/kqueue or when you under DDoS # DNS accf available on 8.0+ accf_data_load="YES" accf_http_load="YES" accf_dns_load="YES" # Async IO system calls aio_load="YES" # Adds NCQ support in FreeBSD # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ # 8.0+ only #ahci_load= #siis_load= # Increase kernel memory size to 3G. # # Use ONLY if you have KVA_PAGES in kernel configuration, and you have more than 3G RAM # Otherwise panic will happen on next reboot! # # It's required for high buffer sizes: kern.ipc.nmbjumbop, kern.ipc.nmbclusters, etc # Useful on highload stateful firewalls, proxies or ZFS fileservers # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #vm.kmem_size="3G" # Older versions of FreeBSD can't tune maxfiles on the fly #kern.maxfiles="200000" # Useful for databases # Sets maximum data size to 1G # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #kern.maxdsiz="1G" # Maximum buffer size(vfs.maxbufspace) # You can check current one via vfs.bufspace # Should be lowered/upped depending on server's load-type # Usually decreased to preserve kmem # (default is 200M) #kern.maxbcache="512M" # Sendfile buffers # For i386 only #kern.ipc.nsfbufs=10240 # syncache Hash table tuning net.inet.tcp.syncache.hashsize=1024 net.inet.tcp.syncache.bucketlimit=100 # Incresed hostcache net.inet.tcp.hostcache.hashsize="16384" net.inet.tcp.hostcache.bucketlimit="100" # TCP control-block Hash table tuning net.inet.tcp.tcbhashsize=4096 # Enable superpages, for 7.2+ only # Also read http://lists.freebsd.org/pipermail/freebsd-hackers/2009-November/030094.html vm.pmap.pg_ps_enabled=1 # Usefull if you are using Intel-Gigabit NIC #hw.em.rxd=4096 #hw.em.txd=4096 #hw.em.rx_process_limit="-1" # Also if you have ALOT interrupts on NIC - play with following parameters # NOTE: You should set them for every NIC #dev.em.0.rx_int_delay: 250 #dev.em.0.tx_int_delay: 250 #dev.em.0.rx_abs_int_delay: 250 #dev.em.0.tx_abs_int_delay: 250 # There is also multithreaded version of em drivers can be found here: # http://people.yandex-team.ru/~wawa/ # # for additional em monitoring and statistics use # `sysctl dev.em.0.stats=1 ; dmesg` # #Same tunings for igb #hw.igb.rxd=4096 #hw.igb.txd=4096 #hw.igb.rx_process_limit=100 # Some useful netisr tunables. See sysctl net.isr #net.isr.defaultqlimit=4096 #net.isr.maxqlimit: 10240 # Bind netisr threads to CPUs #net.isr.bindthreads=1 # Nicer boot logo =) loader_logo="beastie" And finally here is my additions to GENERIC kernel # Just some of them, see also # cat /sys/{i386,amd64,}/conf/NOTES # This one useful only on i386 #options KVA_PAGES=512 # You can play with HZ in environments with high interrupt rate (default is 1000) # 100 is for my notebook to prolong it's battery life #options HZ=100 # Polling is goot on network loads with high packet rates and low-end NICs # NB! Do not enable it if you want more than one netisr thread #options DEVICE_POLLING # Eliminate datacopy on socket read-write # To take advantage with zero copy sockets you should have an MTU of 8K(amd64) # (4k for i386). This req. is only for receiving data. # Read more in man zero_copy_sockets #options ZERO_COPY_SOCKETS # Support TCP sign. Used for IPSec options TCP_SIGNATURE options IPSEC # This ones can be loaded as modules. They described in loader.conf section #options ACCEPT_FILTER_DATA #options ACCEPT_FILTER_HTTP # Adding ipfw, also can be loaded as modules options IPFIREWALL options IPFIREWALL_VERBOSE options IPFIREWALL_VERBOSE_LIMIT=10 options IPFIREWALL_DEFAULT_TO_ACCEPT options IPFIREWALL_FORWARD # Adding kernel NAT options IPFIREWALL_NAT options LIBALIAS # Traffic shaping options DUMMYNET # Divert, i.e. for userspace NAT options IPDIVERT # This is for OpenBSD's pf firewall device pf device pflog # pf's QoS - ALTQ options ALTQ options ALTQ_CBQ # Class Bases Queuing (CBQ) options ALTQ_RED # Random Early Detection (RED) options ALTQ_RIO # RED In/Out options ALTQ_HFSC # Hierarchical Packet Scheduler (HFSC) options ALTQ_PRIQ # Priority Queuing (PRIQ) options ALTQ_NOPCC # Required for SMP build # Pretty console # Manual can be found here http://forums.freebsd.org/showthread.php?t=6134 #options VESA #options SC_PIXEL_MODE # Disable reboot on Ctrl Alt Del #options SC_DISABLE_REBOOT # Change normal|kernel messages color options SC_NORM_ATTR=(FG_GREEN|BG_BLACK) options SC_KERNEL_CONS_ATTR=(FG_YELLOW|BG_BLACK) # More scroll space options SC_HISTORY_SIZE=8192 # Adding hardware crypto device device crypto device cryptodev # Useful network interfaces device vlan device tap #Virtual Ethernet driver device gre #IP over IP tunneling device if_bridge #Bridge interface device pfsync #synchronization interface for PF device carp #Common Address Redundancy Protocol device enc #IPsec interface device lagg #Link aggregation interface device stf #IPv4-IPv6 port # Also for my notebook, but may be used with Opteron #device amdtemp # Support for ECMP. More than one route for destination # Works even with default route so one can use it as LB for two ISP # For now code is unstable and panics (panic: rtfree 2) on route deletions. #options RADIX_MPATH # Multicast routing #options MROUTING #options PIM # DTrace options KDTRACE_HOOKS # all architectures - enable general DTrace hooks options DDB_CTF # all architectures - kernel ELF linker loads CTF data #options KDTRACE_FRAME # amd64-only # Adaptive spining in lockmgr (8.x+) # See http://www.mail-archive.com/[email protected]/msg10782.html options ADAPTIVE_LOCKMGRS # UTF-8 in console (9.x+) #options TEKEN_UTF8 #options TEKEN_XTERM # NCQ support # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ #options ATA_CAM # FreeBSD 9+ # Deadlock resolver thread # For additional information see http://www.mail-archive.com/[email protected]/msg18124.html #options DEADLKRES PS. Also most of FreeBSD's limits can be monitored by # vmstat -z and # limits PPS. variety of network counters can be monitored via # netstat -s In FreeBSD-9 netstat's -Q option appeared, try following command to display netisr stats # netstat -Q PPPS. also see # man 7 tuning PPPPS. I wanted to thank FreeBSD community, especially author of nginx - Igor Sysoev, nginx-ru@ and FreeBSD-performance@ mailing lists for providing useful information about FreeBSD tuning. So here is the question: What tunings are you using on yours FreeBSD servers? You can also post your /etc/sysctl.conf, /boot/loader.conf, kernel options, etc with description of its' meaning (do not copy-paste from sysctl -d). Don't forget to specify server type (web, smb, gateway, etc) Let's share experience!

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• FreeBSD 8.1 unstable network connection

  - by frankcheong

  I have three FreeBSD 8.1 running on three different hardware and therefore consist of different network adapter as well (bce, bge and igb). I found that the network connection is kind of unstable which I have tried to scp some 10MB file and found that I cannot always get the files completed successfully. I have further checked with my network admin and he claim that the problem is being caused by the network driver which cannot support the load whereby he tried to ping using huge packet size (around 15k) and my server will drop packet consistently at a regular interval. I found that this statement may not be valid since the three server is using three different network drive and it would be quite impossible that the same problem is being caused by three different network adapter and thus different network driver. Since then I have tried to tune up the performance by playing around with the /etc/sysctl.conf figures with no luck. kern.ipc.somaxconn=1024 kern.ipc.shmall=3276800 kern.ipc.shmmax=1638400000 # Security net.inet.ip.redirect=0 net.inet.ip.sourceroute=0 net.inet.ip.accept_sourceroute=0 net.inet.icmp.maskrepl=0 net.inet.icmp.log_redirect=0 net.inet.icmp.drop_redirect=1 net.inet.tcp.drop_synfin=1 # Security net.inet.udp.blackhole=1 net.inet.tcp.blackhole=2 # Required by pf net.inet.ip.forwarding=1 #Network Performance Tuning kern.ipc.maxsockbuf=16777216 net.inet.tcp.rfc1323=1 net.inet.tcp.sendbuf_max=16777216 net.inet.tcp.recvbuf_max=16777216 # Setting specifically for 1 or even 10Gbps network net.local.stream.sendspace=262144 net.local.stream.recvspace=262144 net.inet.tcp.local_slowstart_flightsize=10 net.inet.tcp.nolocaltimewait=1 net.inet.tcp.mssdflt=1460 net.inet.tcp.sendbuf_auto=1 net.inet.tcp.sendbuf_inc=16384 net.inet.tcp.recvbuf_auto=1 net.inet.tcp.recvbuf_inc=524288 net.inet.tcp.sendspace=262144 net.inet.tcp.recvspace=262144 net.inet.udp.recvspace=262144 kern.ipc.maxsockbuf=16777216 kern.ipc.nmbclusters=32768 net.inet.tcp.delayed_ack=1 net.inet.tcp.delacktime=100 net.inet.tcp.slowstart_flightsize=179 net.inet.tcp.inflight.enable=1 net.inet.tcp.inflight.min=6144 # Reduce the cache size of slow start connection net.inet.tcp.hostcache.expire=1 Our network admin also claim that they see quite a lot of network up and down from their cisco switch log while I cannot find any up down message inside the dmesg. Have further checked the netstat -s but dont have concrete idea. tcp: 133695291 packets sent 39408539 data packets (3358837321 bytes) 61868 data packets (89472844 bytes) retransmitted 24 data packets unnecessarily retransmitted 0 resends initiated by MTU discovery 50756141 ack-only packets (2148 delayed) 0 URG only packets 0 window probe packets 4372385 window update packets 39781869 control packets 134898031 packets received 72339403 acks (for 3357601899 bytes) 190712 duplicate acks 0 acks for unsent data 59339201 packets (3647021974 bytes) received in-sequence 114 completely duplicate packets (135202 bytes) 27 old duplicate packets 0 packets with some dup. data (0 bytes duped) 42090 out-of-order packets (60817889 bytes) 0 packets (0 bytes) of data after window 0 window probes 3953896 window update packets 64181 packets received after close 0 discarded for bad checksums 0 discarded for bad header offset fields 0 discarded because packet too short 45192 discarded due to memory problems 19945391 connection requests 1323420 connection accepts 0 bad connection attempts 0 listen queue overflows 0 ignored RSTs in the windows 21133581 connections established (including accepts) 21268724 connections closed (including 32737 drops) 207874 connections updated cached RTT on close 207874 connections updated cached RTT variance on close 132439 connections updated cached ssthresh on close 42392 embryonic connections dropped 72339338 segments updated rtt (of 69477829 attempts) 390871 retransmit timeouts 0 connections dropped by rexmit timeout 0 persist timeouts 0 connections dropped by persist timeout 0 Connections (fin_wait_2) dropped because of timeout 13990 keepalive timeouts 2 keepalive probes sent 13988 connections dropped by keepalive 173044 correct ACK header predictions 36947371 correct data packet header predictions 1323420 syncache entries added 0 retransmitted 0 dupsyn 0 dropped 1323420 completed 0 bucket overflow 0 cache overflow 0 reset 0 stale 0 aborted 0 badack 0 unreach 0 zone failures 1323420 cookies sent 0 cookies received 1864 SACK recovery episodes 18005 segment rexmits in SACK recovery episodes 26066896 byte rexmits in SACK recovery episodes 147327 SACK options (SACK blocks) received 87473 SACK options (SACK blocks) sent 0 SACK scoreboard overflow 0 packets with ECN CE bit set 0 packets with ECN ECT(0) bit set 0 packets with ECN ECT(1) bit set 0 successful ECN handshakes 0 times ECN reduced the congestion window udp: 5141258 datagrams received 0 with incomplete header 0 with bad data length field 0 with bad checksum 1 with no checksum 0 dropped due to no socket 129616 broadcast/multicast datagrams undelivered 0 dropped due to full socket buffers 0 not for hashed pcb 5011642 delivered 5016050 datagrams output 0 times multicast source filter matched sctp: 0 input packets 0 datagrams 0 packets that had data 0 input SACK chunks 0 input DATA chunks 0 duplicate DATA chunks 0 input HB chunks 0 HB-ACK chunks 0 input ECNE chunks 0 input AUTH chunks 0 chunks missing AUTH 0 invalid HMAC ids received 0 invalid secret ids received 0 auth failed 0 fast path receives all one chunk 0 fast path multi-part data 0 output packets 0 output SACKs 0 output DATA chunks 0 retransmitted DATA chunks 0 fast retransmitted DATA chunks 0 FR's that happened more than once to same chunk 0 intput HB chunks 0 output ECNE chunks 0 output AUTH chunks 0 ip_output error counter Packet drop statistics: 0 from middle box 0 from end host 0 with data 0 non-data, non-endhost 0 non-endhost, bandwidth rep only 0 not enough for chunk header 0 not enough data to confirm 0 where process_chunk_drop said break 0 failed to find TSN 0 attempt reverse TSN lookup 0 e-host confirms zero-rwnd 0 midbox confirms no space 0 data did not match TSN 0 TSN's marked for Fast Retran Timeouts: 0 iterator timers fired 0 T3 data time outs 0 window probe (T3) timers fired 0 INIT timers fired 0 sack timers fired 0 shutdown timers fired 0 heartbeat timers fired 0 a cookie timeout fired 0 an endpoint changed its cookiesecret 0 PMTU timers fired 0 shutdown ack timers fired 0 shutdown guard timers fired 0 stream reset timers fired 0 early FR timers fired 0 an asconf timer fired 0 auto close timer fired 0 asoc free timers expired 0 inp free timers expired 0 packet shorter than header 0 checksum error 0 no endpoint for port 0 bad v-tag 0 bad SID 0 no memory 0 number of multiple FR in a RTT window 0 RFC813 allowed sending 0 RFC813 does not allow sending 0 times max burst prohibited sending 0 look ahead tells us no memory in interface 0 numbers of window probes sent 0 times an output error to clamp down on next user send 0 times sctp_senderrors were caused from a user 0 number of in data drops due to chunk limit reached 0 number of in data drops due to rwnd limit reached 0 times a ECN reduced the cwnd 0 used express lookup via vtag 0 collision in express lookup 0 times the sender ran dry of user data on primary 0 same for above 0 sacks the slow way 0 window update only sacks sent 0 sends with sinfo_flags !=0 0 unordered sends 0 sends with EOF flag set 0 sends with ABORT flag set 0 times protocol drain called 0 times we did a protocol drain 0 times recv was called with peek 0 cached chunks used 0 cached stream oq's used 0 unread messages abandonded by close 0 send burst avoidance, already max burst inflight to net 0 send cwnd full avoidance, already max burst inflight to net 0 number of map array over-runs via fwd-tsn's ip: 137814085 total packets received 0 bad header checksums 0 with size smaller than minimum 0 with data size < data length 0 with ip length > max ip packet size 0 with header length < data size 0 with data length < header length 0 with bad options 0 with incorrect version number 1200 fragments received 0 fragments dropped (dup or out of space) 0 fragments dropped after timeout 300 packets reassembled ok 137813009 packets for this host 530 packets for unknown/unsupported protocol 0 packets forwarded (0 packets fast forwarded) 61 packets not forwardable 0 packets received for unknown multicast group 0 redirects sent 137234598 packets sent from this host 0 packets sent with fabricated ip header 685307 output packets dropped due to no bufs, etc. 52 output packets discarded due to no route 300 output datagrams fragmented 1200 fragments created 0 datagrams that can't be fragmented 0 tunneling packets that can't find gif 0 datagrams with bad address in header icmp: 0 calls to icmp_error 0 errors not generated in response to an icmp message Output histogram: echo reply: 305 0 messages with bad code fields 0 messages less than the minimum length 0 messages with bad checksum 0 messages with bad length 0 multicast echo requests ignored 0 multicast timestamp requests ignored Input histogram: destination unreachable: 530 echo: 305 305 message responses generated 0 invalid return addresses 0 no return routes ICMP address mask responses are disabled igmp: 0 messages received 0 messages received with too few bytes 0 messages received with wrong TTL 0 messages received with bad checksum 0 V1/V2 membership queries received 0 V3 membership queries received 0 membership queries received with invalid field(s) 0 general queries received 0 group queries received 0 group-source queries received 0 group-source queries dropped 0 membership reports received 0 membership reports received with invalid field(s) 0 membership reports received for groups to which we belong 0 V3 reports received without Router Alert 0 membership reports sent arp: 376748 ARP requests sent 3207 ARP replies sent 245245 ARP requests received 80845 ARP replies received 326090 ARP packets received 267712 total packets dropped due to no ARP entry 108876 ARP entrys timed out 0 Duplicate IPs seen ip6: 2226633 total packets received 0 with size smaller than minimum 0 with data size < data length 0 with bad options 0 with incorrect version number 0 fragments received 0 fragments dropped (dup or out of space) 0 fragments dropped after timeout 0 fragments that exceeded limit 0 packets reassembled ok 2226633 packets for this host 0 packets forwarded 0 packets not forwardable 0 redirects sent 2226633 packets sent from this host 0 packets sent with fabricated ip header 0 output packets dropped due to no bufs, etc. 8 output packets discarded due to no route 0 output datagrams fragmented 0 fragments created 0 datagrams that can't be fragmented 0 packets that violated scope rules 0 multicast packets which we don't join Input histogram: UDP: 2226633 Mbuf statistics: 962679 one mbuf 1263954 one ext mbuf 0 two or more ext mbuf 0 packets whose headers are not continuous 0 tunneling packets that can't find gif 0 packets discarded because of too many headers 0 failures of source address selection Source addresses selection rule applied: icmp6: 0 calls to icmp6_error 0 errors not generated in response to an icmp6 message 0 errors not generated because of rate limitation 0 messages with bad code fields 0 messages < minimum length 0 bad checksums 0 messages with bad length Histogram of error messages to be generated: 0 no route 0 administratively prohibited 0 beyond scope 0 address unreachable 0 port unreachable 0 packet too big 0 time exceed transit 0 time exceed reassembly 0 erroneous header field 0 unrecognized next header 0 unrecognized option 0 redirect 0 unknown 0 message responses generated 0 messages with too many ND options 0 messages with bad ND options 0 bad neighbor solicitation messages 0 bad neighbor advertisement messages 0 bad router solicitation messages 0 bad router advertisement messages 0 bad redirect messages 0 path MTU changes rip6: 0 messages received 0 checksum calculations on inbound 0 messages with bad checksum 0 messages dropped due to no socket 0 multicast messages dropped due to no socket 0 messages dropped due to full socket buffers 0 delivered 0 datagrams output netstat -m 516/5124/5640 mbufs in use (current/cache/total) 512/1634/2146/32768 mbuf clusters in use (current/cache/total/max) 512/1536 mbuf+clusters out of packet secondary zone in use (current/cache) 0/1303/1303/12800 4k (page size) jumbo clusters in use (current/cache/total/max) 0/0/0/6400 9k jumbo clusters in use (current/cache/total/max) 0/0/0/3200 16k jumbo clusters in use (current/cache/total/max) 1153K/9761K/10914K bytes allocated to network (current/cache/total) 0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters) 0/0/0 requests for jumbo clusters denied (4k/9k/16k) 0/8/6656 sfbufs in use (current/peak/max) 0 requests for sfbufs denied 0 requests for sfbufs delayed 0 requests for I/O initiated by sendfile 0 calls to protocol drain routines Anyone got an idea what might be the possible cause?

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• FreeBSD performance tuning. Sysctls, loader.conf, kernel

  - by SaveTheRbtz

  I wanted to share knowledge of tuning FreeBSD via sysctl.conf/loader.conf/KENCONF. It was initially based on Igor Sysoev's (author of nginx) presentation about FreeBSD tuning up to 100,000-200,000 active connections. Tunings are for FreeBSD-CURRENT. Since 7.2 amd64 some of them are tuned well by default. Prior 7.0 some of them are boot only (set via /boot/loader.conf) or does not exist at all. sysctl.conf: # No zero mapping feature # May break wine # (There are also reports about broken samba3) #security.bsd.map_at_zero=0 # If you have really busy webserver with apache13 you may run out of processes #kern.maxproc=10000 # Same for servers with apache2 / Pound #kern.threads.max_threads_per_proc=4096 # Max. backlog size kern.ipc.somaxconn=4096 # Shared memory // 7.2+ can use shared memory > 2Gb kern.ipc.shmmax=2147483648 # Sockets kern.ipc.maxsockets=204800 # Can cause this on older kernels: # http://old.nabble.com/Significant-performance-regression-for-increased-maxsockbuf-on-8.0-RELEASE-tt26745981.html#a26745981 ) kern.ipc.maxsockbuf=10485760 # Mbuf 2k clusters (on amd64 7.2+ 25600 is default) # For such high value vm.kmem_size must be increased to 3G kern.ipc.nmbclusters=262144 # Jumbo pagesize(_SC_PAGESIZE) clusters # Used as general packet storage for jumbo frames # can be monitored via `netstat -m` #kern.ipc.nmbjumbop=262144 # Jumbo 9k/16k clusters # If you are using them #kern.ipc.nmbjumbo9=65536 #kern.ipc.nmbjumbo16=32768 # For lower latency you can decrease scheduler's maximum time slice # default: stathz/10 (~ 13) #kern.sched.slice=1 # Increase max command-line length showed in `ps` (e.g for Tomcat/Java) # Default is PAGE_SIZE / 16 or 256 on x86 # This avoids commands to be presented as [executable] in `ps` # For more info see: http://www.freebsd.org/cgi/query-pr.cgi?pr=120749 kern.ps_arg_cache_limit=4096 # Every socket is a file, so increase them kern.maxfiles=204800 kern.maxfilesperproc=200000 kern.maxvnodes=200000 # On some systems HPET is almost 2 times faster than default ACPI-fast # Useful on systems with lots of clock_gettime / gettimeofday calls # See http://old.nabble.com/ACPI-fast-default-timecounter,-but-HPET-83--faster-td23248172.html # After revision 222222 HPET became default: http://svnweb.freebsd.org/base?view=revision&revision=222222 kern.timecounter.hardware=HPET # Small receive space, only usable on http-server, on file server this # should be increased to 65535 or even more #net.inet.tcp.recvspace=8192 # This is useful on Fat-Long-Pipes #net.inet.tcp.recvbuf_max=10485760 #net.inet.tcp.recvbuf_inc=65535 # Small send space is useful for http servers that serve small files # Autotuned since 7.x net.inet.tcp.sendspace=16384 # This is useful on Fat-Long-Pipes #net.inet.tcp.sendbuf_max=10485760 #net.inet.tcp.sendbuf_inc=65535 # Turn off receive autotuning # You can play with it. #net.inet.tcp.recvbuf_auto=0 #net.inet.tcp.sendbuf_auto=0 # This should be enabled if you going to use big spaces (>64k) # Also timestamp field is useful when using syncookies net.inet.tcp.rfc1323=1 # Turn this off on high-speed, lossless connections (LAN 1Gbit+) # If you set it there is no need in TCP_NODELAY sockopt (see man tcp) net.inet.tcp.delayed_ack=0 # This feature is useful if you are serving data over modems, Gigabit Ethernet, # or even high speed WAN links (or any other link with a high bandwidth delay product), # especially if you are also using window scaling or have configured a large send window. # Automatically disables on small RTT ( http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_subr.c?#rev1.237 ) # This sysctl was removed in 10-CURRENT: # See: http://www.mail-archive.com/[email protected]/msg06178.html #net.inet.tcp.inflight.enable=0 # TCP slowstart algorithm tunings # We assuming we have very fast clients #net.inet.tcp.slowstart_flightsize=100 #net.inet.tcp.local_slowstart_flightsize=100 # Disable randomizing of ports to avoid false RST # Before usage check SA here www.bsdcan.org/2006/papers/ImprovingTCPIP.pdf # (it's also says that port randomization auto-disables at some conn.rates, but I didn't checked it thou) #net.inet.ip.portrange.randomized=0 # Increase portrange # For outgoing connections only. Good for seed-boxes and ftp servers. net.inet.ip.portrange.first=1024 net.inet.ip.portrange.last=65535 # # stops route cache degregation during a high-bandwidth flood # http://www.freebsd.org/doc/en/books/handbook/securing-freebsd.html #net.inet.ip.rtexpire=2 net.inet.ip.rtminexpire=2 net.inet.ip.rtmaxcache=1024 # Security net.inet.ip.redirect=0 net.inet.ip.sourceroute=0 net.inet.ip.accept_sourceroute=0 net.inet.icmp.maskrepl=0 net.inet.icmp.log_redirect=0 net.inet.icmp.drop_redirect=1 net.inet.tcp.drop_synfin=1 # # There is also good example of sysctl.conf with comments: # http://www.thern.org/projects/sysctl.conf # # icmp may NOT rst, helpful for those pesky spoofed # icmp/udp floods that end up taking up your outgoing # bandwidth/ifqueue due to all that outgoing RST traffic. # #net.inet.tcp.icmp_may_rst=0 # Security net.inet.udp.blackhole=1 net.inet.tcp.blackhole=2 # IPv6 Security # For more info see http://www.fosslc.org/drupal/content/security-implications-ipv6 # Disable Node info replies # To see this vulnerability in action run `ping6 -a sglAac ::1` or `ping6 -w ::1` on unprotected node net.inet6.icmp6.nodeinfo=0 # Turn on IPv6 privacy extensions # For more info see proposal http://unix.derkeiler.com/Mailing-Lists/FreeBSD/net/2008-06/msg00103.html net.inet6.ip6.use_tempaddr=1 net.inet6.ip6.prefer_tempaddr=1 # Disable ICMP redirect net.inet6.icmp6.rediraccept=0 # Disable acceptation of RA and auto linklocal generation if you don't use them #net.inet6.ip6.accept_rtadv=0 #net.inet6.ip6.auto_linklocal=0 # Increases default TTL, sometimes useful # Default is 64 net.inet.ip.ttl=128 # Lessen max segment life to conserve resources # ACK waiting time in miliseconds # (default: 30000. RFC from 1979 recommends 120000) net.inet.tcp.msl=5000 # Max bumber of timewait sockets net.inet.tcp.maxtcptw=200000 # Don't use tw on local connections # As of 15 Apr 2009. Igor Sysoev says that nolocaltimewait has some buggy realization. # So disable it or now till get fixed #net.inet.tcp.nolocaltimewait=1 # FIN_WAIT_2 state fast recycle net.inet.tcp.fast_finwait2_recycle=1 # Time before tcp keepalive probe is sent # default is 2 hours (7200000) #net.inet.tcp.keepidle=60000 # Should be increased until net.inet.ip.intr_queue_drops is zero net.inet.ip.intr_queue_maxlen=4096 # Interrupt handling via multiple CPU, but with context switch. # You can play with it. Default is 1; #net.isr.direct=0 # This is for routers only #net.inet.ip.forwarding=1 #net.inet.ip.fastforwarding=1 # This speed ups dummynet when channel isn't saturated net.inet.ip.dummynet.io_fast=1 # Increase dummynet(4) hash #net.inet.ip.dummynet.hash_size=2048 #net.inet.ip.dummynet.max_chain_len # Should be increased when you have A LOT of files on server # (Increase until vfs.ufs.dirhash_mem becomes lower) vfs.ufs.dirhash_maxmem=67108864 # Note from commit http://svn.freebsd.org/base/head@211031 : # For systems with RAID volumes and/or virtualization envirnments, where # read performance is very important, increasing this sysctl tunable to 32 # or even more will demonstratively yield additional performance benefits. vfs.read_max=32 # Explicit Congestion Notification (see http://en.wikipedia.org/wiki/Explicit_Congestion_Notification) net.inet.tcp.ecn.enable=1 # Flowtable - flow caching mechanism # Useful for routers #net.inet.flowtable.enable=1 #net.inet.flowtable.nmbflows=65535 # Extreme polling tuning #kern.polling.burst_max=1000 #kern.polling.each_burst=1000 #kern.polling.reg_frac=100 #kern.polling.user_frac=1 #kern.polling.idle_poll=0 # IPFW dynamic rules and timeouts tuning # Increase dyn_buckets till net.inet.ip.fw.curr_dyn_buckets is lower net.inet.ip.fw.dyn_buckets=65536 net.inet.ip.fw.dyn_max=65536 net.inet.ip.fw.dyn_ack_lifetime=120 net.inet.ip.fw.dyn_syn_lifetime=10 net.inet.ip.fw.dyn_fin_lifetime=2 net.inet.ip.fw.dyn_short_lifetime=10 # Make packets pass firewall only once when using dummynet # i.e. packets going thru pipe are passing out from firewall with accept #net.inet.ip.fw.one_pass=1 # shm_use_phys Wires all shared pages, making them unswappable # Use this to lessen Virtual Memory Manager's work when using Shared Mem. # Useful for databases #kern.ipc.shm_use_phys=1 # ZFS # Enable prefetch. Useful for sequential load type i.e fileserver. # FreeBSD sets vfs.zfs.prefetch_disable to 1 on any i386 systems and # on any amd64 systems with less than 4GB of avaiable memory # For additional info check this nabble thread http://old.nabble.com/Samba-read-speed-performance-tuning-td27964534.html #vfs.zfs.prefetch_disable=0 # On highload servers you may notice following message in dmesg: # "Approaching the limit on PV entries, consider increasing either the # vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable" vm.pmap.shpgperproc=2048 loader.conf: # Accept filters for data, http and DNS requests # Useful when your software uses select() instead of kevent/kqueue or when you under DDoS # DNS accf available on 8.0+ accf_data_load="YES" accf_http_load="YES" accf_dns_load="YES" # Async IO system calls aio_load="YES" # Linux specific devices in /dev # As for 8.1 it only /dev/full #lindev_load="YES" # Adds NCQ support in FreeBSD # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ # 8.0+ only #ahci_load="YES" #siis_load="YES" # FreeBSD 8.2+ # New Congestion Control for FreeBSD # http://caia.swin.edu.au/urp/newtcp/tools/cc_chd-readme-0.1.txt # http://www.ietf.org/proceedings/78/slides/iccrg-5.pdf # Initial merge commit message http://www.mail-archive.com/[email protected]/msg31410.html #cc_chd_load="YES" # Increase kernel memory size to 3G. # # Use ONLY if you have KVA_PAGES in kernel configuration, and you have more than 3G RAM # Otherwise panic will happen on next reboot! # # It's required for high buffer sizes: kern.ipc.nmbjumbop, kern.ipc.nmbclusters, etc # Useful on highload stateful firewalls, proxies or ZFS fileservers # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #vm.kmem_size="3G" # If your server has lots of swap (>4Gb) you should increase following value # according to http://lists.freebsd.org/pipermail/freebsd-hackers/2009-October/029616.html # Otherwise you'll be getting errors # "kernel: swap zone exhausted, increase kern.maxswzone" # kern.maxswzone="256M" # Older versions of FreeBSD can't tune maxfiles on the fly #kern.maxfiles="200000" # Useful for databases # Sets maximum data size to 1G # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #kern.maxdsiz="1G" # Maximum buffer size(vfs.maxbufspace) # You can check current one via vfs.bufspace # Should be lowered/upped depending on server's load-type # Usually decreased to preserve kmem # (default is 10% of mem) #kern.maxbcache="512M" # Sendfile buffers # For i386 only #kern.ipc.nsfbufs=10240 # FreeBSD 9+ # HPET "legacy route" support. It should allow HPET to work per-CPU # See http://www.mail-archive.com/[email protected]/msg03603.html #hint.atrtc.0.clock=0 #hint.attimer.0.clock=0 #hint.hpet.0.legacy_route=1 # syncache Hash table tuning net.inet.tcp.syncache.hashsize=1024 net.inet.tcp.syncache.bucketlimit=512 net.inet.tcp.syncache.cachelimit=65536 # Increased hostcache # Later host cache can be viewed via net.inet.tcp.hostcache.list hidden sysctl # Very useful for it's RTT RTTVAR # Must be power of two net.inet.tcp.hostcache.hashsize=65536 # hashsize * bucketlimit (which is 30 by default) # It allocates 255Mb (1966080*136) of RAM net.inet.tcp.hostcache.cachelimit=1966080 # TCP control-block Hash table tuning net.inet.tcp.tcbhashsize=4096 # Disable ipfw deny all # Should be uncommented when there is a chance that # kernel and ipfw binary may be out-of sync on next reboot #net.inet.ip.fw.default_to_accept=1 # # SIFTR (Statistical Information For TCP Research) is a kernel module that # logs a range of statistics on active TCP connections to a log file. # See prerelease notes http://groups.google.com/group/mailing.freebsd.current/browse_thread/thread/b4c18be6cdce76e4 # and man 4 sitfr #siftr_load="YES" # Enable superpages, for 7.2+ only # Also read http://lists.freebsd.org/pipermail/freebsd-hackers/2009-November/030094.html vm.pmap.pg_ps_enabled=1 # Usefull if you are using Intel-Gigabit NIC #hw.em.rxd=4096 #hw.em.txd=4096 #hw.em.rx_process_limit="-1" # Also if you have ALOT interrupts on NIC - play with following parameters # NOTE: You should set them for every NIC #dev.em.0.rx_int_delay: 250 #dev.em.0.tx_int_delay: 250 #dev.em.0.rx_abs_int_delay: 250 #dev.em.0.tx_abs_int_delay: 250 # There is also multithreaded version of em/igb drivers can be found here: # http://people.yandex-team.ru/~wawa/ # # for additional em monitoring and statistics use # sysctl dev.em.0.stats=1 ; dmesg # sysctl dev.em.0.debug=1 ; dmesg # Also after r209242 (-CURRENT) there is a separate sysctl for each stat variable; # Same tunings for igb #hw.igb.rxd=4096 #hw.igb.txd=4096 #hw.igb.rx_process_limit=100 # Some useful netisr tunables. See sysctl net.isr #net.isr.maxthreads=4 #net.isr.defaultqlimit=4096 #net.isr.maxqlimit: 10240 # Bind netisr threads to CPUs #net.isr.bindthreads=1 # # FreeBSD 9.x+ # Increase interface send queue length # See commit message http://svn.freebsd.org/viewvc/base?view=revision&revision=207554 #net.link.ifqmaxlen=1024 # Nicer boot logo =) loader_logo="beastie" And finally here is KERNCONF: # Just some of them, see also # cat /sys/{i386,amd64,}/conf/NOTES # This one useful only on i386 #options KVA_PAGES=512 # You can play with HZ in environments with high interrupt rate (default is 1000) # 100 is for my notebook to prolong it's battery life #options HZ=100 # Polling is goot on network loads with high packet rates and low-end NICs # NB! Do not enable it if you want more than one netisr thread #options DEVICE_POLLING # Eliminate datacopy on socket read-write # To take advantage with zero copy sockets you should have an MTU >= 4k # This req. is only for receiving data. # Read more in man zero_copy_sockets # Also this epic thread on kernel trap: # http://kerneltrap.org/node/6506 # Here Linus says that "anybody that does it that way (FreeBSD) is totally incompetent" #options ZERO_COPY_SOCKETS # Support TCP sign. Used for IPSec options TCP_SIGNATURE # There was stackoverflow found in KAME IPSec stack: # See http://secunia.com/advisories/43995/ # For quick workaround you can use `ipfw add deny proto ipcomp` options IPSEC # This ones can be loaded as modules. They described in loader.conf section #options ACCEPT_FILTER_DATA #options ACCEPT_FILTER_HTTP # Adding ipfw, also can be loaded as modules options IPFIREWALL # On 8.1+ you can disable verbose to see blocked packets on ipfw0 interface. # Also there is no point in compiling verbose into the kernel, because # now there is net.inet.ip.fw.verbose tunable. #options IPFIREWALL_VERBOSE #options IPFIREWALL_VERBOSE_LIMIT=10 options IPFIREWALL_FORWARD # Adding kernel NAT options IPFIREWALL_NAT options LIBALIAS # Traffic shaping options DUMMYNET # Divert, i.e. for userspace NAT options IPDIVERT # This is for OpenBSD's pf firewall device pf device pflog # pf's QoS - ALTQ options ALTQ options ALTQ_CBQ # Class Bases Queuing (CBQ) options ALTQ_RED # Random Early Detection (RED) options ALTQ_RIO # RED In/Out options ALTQ_HFSC # Hierarchical Packet Scheduler (HFSC) options ALTQ_PRIQ # Priority Queuing (PRIQ) options ALTQ_NOPCC # Required for SMP build # Pretty console # Manual can be found here http://forums.freebsd.org/showthread.php?t=6134 #options VESA #options SC_PIXEL_MODE # Disable reboot on Ctrl Alt Del #options SC_DISABLE_REBOOT # Change normal|kernel messages color options SC_NORM_ATTR=(FG_GREEN|BG_BLACK) options SC_KERNEL_CONS_ATTR=(FG_YELLOW|BG_BLACK) # More scroll space options SC_HISTORY_SIZE=8192 # Adding hardware crypto device device crypto device cryptodev # Useful network interfaces device vlan device tap #Virtual Ethernet driver device gre #IP over IP tunneling device if_bridge #Bridge interface device pfsync #synchronization interface for PF device carp #Common Address Redundancy Protocol device enc #IPsec interface device lagg #Link aggregation interface device stf #IPv4-IPv6 port # Also for my notebook, but may be used with Opteron device amdtemp # Same for Intel processors device coretemp # man 4 cpuctl device cpuctl # CPU control pseudo-device # Support for ECMP. More than one route for destination # Works even with default route so one can use it as LB for two ISP # For now code is unstable and panics (panic: rtfree 2) on route deletions. #options RADIX_MPATH # Multicast routing #options MROUTING #options PIM # Debug & DTrace options KDB # Kernel debugger related code options KDB_TRACE # Print a stack trace for a panic options KDTRACE_FRAME # amd64-only(?) options KDTRACE_HOOKS # all architectures - enable general DTrace hooks #options DDB #options DDB_CTF # all architectures - kernel ELF linker loads CTF data # Adaptive spining in lockmgr (8.x+) # See http://www.mail-archive.com/[email protected]/msg10782.html options ADAPTIVE_LOCKMGRS # UTF-8 in console (8.x+) #options TEKEN_UTF8 # FreeBSD 8.1+ # Deadlock resolver thread # For additional information see http://www.mail-archive.com/[email protected]/msg18124.html # (FYI: "resolution" is panic so use with caution) #options DEADLKRES # Increase maximum size of Raw I/O and sendfile(2) readahead #options MAXPHYS=(1024*1024) #options MAXBSIZE=(1024*1024) # For scheduler debug enable following option. # Debug will be available via `kern.sched.stats` sysctl # For more information see http://svnweb.freebsd.org/base/head/sys/conf/NOTES?view=markup #options SCHED_STATS If you are tuning network for maximum performance you may wish to play with ifconfig options like: # You can list all capabilities via `ifconfig -m` ifconfig [-]rxcsum [-]txcsum [-]tso [-]lro mtu In case you've enabled DDB in kernel config, you should edit your /etc/ddb.conf and add something like this to enable automatic reboot (and textdump as bonus): script kdb.enter.panic=textdump set; capture on; show pcpu; bt; ps; alltrace; capture off; call doadump; reset script kdb.enter.default=textdump set; capture on; bt; ps; capture off; call doadump; reset And do not forget to add ddb_enable="YES" to /etc/rc.conf Since FreeBSD 9 you can select to enable/disable flowcontrol on your NIC: # See http://en.wikipedia.org/wiki/Ethernet_flow_control and # http://www.mail-archive.com/[email protected]/msg07927.html for additional info ifconfig bge0 media auto mediaopt flowcontrol PS. Also most of FreeBSD's limits can be monitored by # vmstat -z and # limits PPS. variety of network counters can be monitored via # netstat -s In FreeBSD-9 netstat's -Q option appeared, try following command to display netisr stats # netstat -Q PPPS. also see # man 7 tuning PPPPS. I wanted to thank FreeBSD community, especially author of nginx - Igor Sysoev, nginx-ru@ and FreeBSD-performance@ mailing lists for providing useful information about FreeBSD tuning. FreeBSD WIP * Whats cooking for FreeBSD 7? * Whats cooking for FreeBSD 8? * Whats cooking for FreeBSD 9? So here is the question: What tunings are you using on yours FreeBSD servers? You can also post your /etc/sysctl.conf, /boot/loader.conf, kernel options, etc with description of its' meaning (do not copy-paste from sysctl -d). Don't forget to specify server type (web, smb, gateway, etc) Let's share experience!

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