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  • Load balancing with rsync

    - by David
    i have 2 server with public ip: SERVER A - 10.10.10.11 SERVER B - 10.10.10.12 both of them are centos 6 in OS, installed nginx with php-fpm, 2 exact same website stored at: /var/www/html. Domain with: myxdomain.com and dns hosted with cloudflare ( since cloudflare do support round robin ) to point the domain to A record of 10.10.10.11 and 10.10.10.12. I know that round robin dns does not cover the failover or fallover, but it does not matter, what i need is: How do i sync the both content of /var/www/html server A and server B to be exactly same? Lets say: 1) user uploaded their file to server A, the file content will be sync to server B as well. 2) user uploaded their file to server B, the file content will be sync to server A as well. rsync will be good choice here? Any example of command line and cronjob time that suitable? thanks

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  • Securely wiping a file on a tmpfs

    - by Nanzikambe
    I have a script that decrypts some data to a tmpfs, the directory is secure (permissions), the machine's swap is encrypted (random key on boot) and when the script is done it does a 35 pass wipe (Peter Gutmann) of the cleartext on the tmpfs . I do this because I'm aware wiping files on a journaling file system is insecure, data may be recovered. For discussion, here're the relevant bits extracted: # make the tmpfs mkdir /mnt/tmpfs chmod 0700 /mnt/tmpfs mount -t tmpfs -o size=1M tmpfs /mnt/tmpfs cd /mnt/tmpfs # decrypt the data gpg -o - <crypted_input_file> | \ tar -xjpf - # do processing stuff # wipe contents find . -type f -exec bcwipe -I {} ';' # nuke the tmpfs cd .. umount -f /mnt/tmpfs rm -fR /mnt/tmpfs So, my question, assuming for the moment that nobody is able to read the cleartext in the tmpfs while it exists (I use umask to set cleartext to 0600), is there any way any trace of the cleartext could remain either in memory or on disk after the snippet above completes?

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  • Secondary backup server

    - by verdy
    I've been given a task to implement a backup solution in the event of our website goes down. It is a dedicated server running centos 6. From what i've experience on our server, our server may go down because of PHP application crash or hardware failure. I have couple of questions: In the first case, is it possible to get the server restart the PHP automatically, how can I do that? Because in my mind, if it is only the application that goes down, probably I can still make use of the server itself. In the second case, can I redirect a request to a secondary server? How can I do that? What do I need other than another server? For now it is gonna be a simple server which shows the user a static landing page so later the system notify us via email that the primary server went down so that we can restart the server manually. Is it possible to setup just a vps or even a shared server for the secondary server ? As I think there is only gonna be a static page. Thanks. Any help would be much appreciated

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  • Windows can see Ubuntu Server printer, but can't print to it

    - by Mike
    I have an old desktop that I'm trying to set up as a home backup/print server. Backup was trivial, but am having issues getting the printing to work. The printer is connected to the server running Ubuntu Server 9.10 (no gui). If I access the printer via http://hostname:631/printers/, I am able to print a test page, so I know the printer is working; however, I am having no luck from Windows. Windows can see the printer when browsed via \hostname\, but I am unable to connect. Windows says "Windows cannot connect to the printer" without indicating why. Any suggestions? From /etc/samba/smb.conf: [global] workgroup = WORKGROUP dns proxy = no security = user username map = /etc/samba/smbusers encrypt passwords = true passdb backend = tdbsam obey pam restrictions = yes unix password sync = yes passwd program = /usr/bin/passwd %u passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* . pam password change = yes map to guest = bad user load printers = yes printing = cups printcap name = cups [printers] comment = All Printers browseable = no path = /var/spool/samba writable = no printable = yes guest ok = yes read only = yes create mask = 0700 [print$] comment = Printer Drivers path = /var/lib/samba/printers browseable = yes read only = yes guest ok = yes From /etc/cups/cupsd.conf: LogLevel warn SystemGroup lpadmin Port 631 Listen /var/run/cups/cups.sock Browsing On BrowseOrder allow,deny BrowseAllow all BrowseRemoteProtocols CUPS BrowseAddress @LOCAL BrowseLocalProtocols CUPS dnssd DefaultAuthType Basic <Location /> Order allow,deny Allow all </Location> <Location /admin> Order allow,deny Allow all </Location> <Location /admin/conf> AuthType Default Require user @SYSTEM Order allow,deny Allow all </Location> <Policy default> <Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job CUPS-Move-Job CUPS-Get-Document> Require user @OWNER @SYSTEM Order deny,allow </Limit> <Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default CUPS-Get-Devices> AuthType Default Require user @SYSTEM Order deny,allow </Limit> <Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After CUPS-Accept-Jobs CUPS-Reject-Jobs> AuthType Default Require user @SYSTEM Order deny,allow </Limit> <Limit CUPS-Authenticate-Job> Require user @OWNER @SYSTEM Order deny,allow </Limit> <Limit All> Order deny,allow </Limit> </Policy> <Policy authenticated> <Limit Create-Job Print-Job Print-URI> AuthType Default Order deny,allow </Limit> <Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job CUPS-Move-Job CUPS-Get-Document> AuthType Default Require user @OWNER @SYSTEM Order deny,allow </Limit> <Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default> AuthType Default Require user @SYSTEM Order deny,allow </Limit> <Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After CUPS-Accept-Jobs CUPS-Reject-Jobs> AuthType Default Require user @SYSTEM Order deny,allow </Limit> <Limit Cancel-Job CUPS-Authenticate-Job> AuthType Default Require user @OWNER @SYSTEM Order deny,allow </Limit> <Limit All> Order deny,allow </Limit> </Policy>

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  • OpenVPN: ifup tap0 drops all connections

    - by raspi
    I'm trying to create star shaped "virtual" LAN with OpenVPN which is not connected to physical network. ie. tap0 packets should not go to eth0. Packet should only go through OpenVPN to connected clients. This setup works with my OpenVPN testing machine which runs Virtual Box but not on my actual server which is running on top of Xen. Both servers are running Ubuntu Intrepid. /etc/network/interfaces: iface tap0 inet manual address 10.10.10.1 netmask 255.255.255.0 gateway 10.10.10.1 /etc/openvpn/server.conf mode server tls-server port 1194 proto udp dev tap client-to-client ca /etc/openvpn/easy-rsa/keys/ca.crt cert /etc/openvpn/easy-rsa/keys/servername.crt key /etc/openvpn/easy-rsa/keys/servername.key dh /etc/openvpn/easy-rsa/keys/dh384.pem ifconfig-pool-persist ipp.txt server-bridge 10.10.10.1 255.255.255.0 10.10.10.128 10.10.10.250 push .route 10.10.10.1 255.255.255.0 keepalive 5 60 comp-lzo persist-key persist-tun status /var/log/openvpn-status.log log-append /var/log/openvpn.log verb 3 user nobody group nogroup ifup tap0 on Virtual Box: everything ok, SSH keeps running. But on Xen SSH connection drops and I have to reboot whole machine. What I'm missing?

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  • installing rpm packages on ubuntu

    - by Hulk
    In ubuntu i have downloaded flash rpm,how to install it.i am new to ubuntu and i have tried the following alien -k flash-plugin-10.0.45.2-release.i386.rpm alien -i flash-plugin-10.0.45.2-release.i386.rpm rpm -i flash-plugin-10.0.45.2-release.i386.rpm //this works in rhel versions The above doesn't seem to work.. Thanks..

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  • Lighttpd not cleanly restarting (address already in use)

    - by NilObject
    When doing a dist-upgrade recently, my lighttpd-1.4.19 install on Ubuntu 8.0.4 has begun failing to restart or reload properly with the /etc/init.d/lighttpd restart command. ~$ sudo /etc/init.d/lighttpd restart * Stopping web server lighttpd ...done. * Starting web server lighttpd 2009-06-13 04:06:36: (network.c.300) can't bind to port: 80 Address already in use ...fail! The same error occurs when I do a reload. The way I get around it is to kill lighttpd and then issue the start command, but it seems like I shouldn't have to do that :) I've looked at my config files, and can't spot any immediate errors. Does anyone have any ideas what can be causing this error? This seems to be the latest version as of writing this question that is available via the apt-get route. My config file is: # Debian lighttpd configuration file # ############ Options you really have to take care of #################### ## modules to load # mod_access, mod_accesslog and mod_alias are loaded by default # all other module should only be loaded if neccesary # - saves some time # - saves memory server.modules = ( "mod_access", "mod_alias", "mod_accesslog", "mod_compress", "mod_fastcgi", "mod_rewrite", "mod_redirect", ) ## a static document-root, for virtual-hosting take look at the ## server.virtual-* options server.document-root = "/var/www/" ## where to send error-messages to server.errorlog = "/var/log/lighttpd/error.log" fastcgi.server = (".php" => (( "bin-path" => "/usr/bin/php5-cgi", "socket" => "/tmp/php.socket" ))) ## files to check for if .../ is requested index-file.names = ( "index.php", "index.html", "index.htm", "default.htm", "index.lighttpd.html" ) ## Use the "Content-Type" extended attribute to obtain mime type if possible # mimetype.use-xattr = "enable" #### accesslog module accesslog.filename = "/var/log/lighttpd/access.log" ## deny access the file-extensions # # ~ is for backupfiles from vi, emacs, joe, ... # .inc is often used for code includes which should in general not be part # of the document-root url.access-deny = ( "~", ".inc" ) ## # which extensions should not be handle via static-file transfer # # .php, .pl, .fcgi are most often handled by mod_fastcgi or mod_cgi static-file.exclude-extensions = ( ".php", ".pl", ".fcgi" ) mimetype.assign = ( ".pdf" => "application/pdf", ".sig" => "application/pgp-signature", ".spl" => "application/futuresplash", ".class" => "application/octet-stream", ".ps" => "application/postscript", ".torrent" => "application/x-bittorrent", ".dvi" => "application/x-dvi", ".gz" => "application/x-gzip", ".pac" => "application/x-ns-proxy-autoconfig", ".swf" => "application/x-shockwave-flash", ".tar.gz" => "application/x-tgz", ".tgz" => "application/x-tgz", ".tar" => "application/x-tar", ".zip" => "application/zip", ".mp3" => "audio/mpeg", ".m3u" => "audio/x-mpegurl", ".wma" => "audio/x-ms-wma", ".wax" => "audio/x-ms-wax", ".ogg" => "audio/x-wav", ".wav" => "audio/x-wav", ".gif" => "image/gif", ".jpg" => "image/jpeg", ".jpeg" => "image/jpeg", ".png" => "image/png", ".xbm" => "image/x-xbitmap", ".xpm" => "image/x-xpixmap", ".xwd" => "image/x-xwindowdump", ".css" => "text/css", ".html" => "text/html", ".htm" => "text/html", ".js" => "text/javascript", ".asc" => "text/plain", ".c" => "text/plain", ".conf" => "text/plain", ".text" => "text/plain", ".txt" => "text/plain", ".dtd" => "text/xml", ".xml" => "text/xml", ".rss" => "application/rss+xml", ".mpeg" => "video/mpeg", ".mpg" => "video/mpeg", ".mov" => "video/quicktime", ".qt" => "video/quicktime", ".avi" => "video/x-msvideo", ".asf" => "video/x-ms-asf", ".asx" => "video/x-ms-asf", ".wmv" => "video/x-ms-wmv", ".bz2" => "application/x-bzip", ".tbz" => "application/x-bzip-compressed-tar", ".tar.bz2" => "application/x-bzip-compressed-tar" ) include_shell "/usr/share/lighttpd/include-conf-enabled.pl" My /etc/init.d/lighttpd script is (untouched from installation): #!/bin/sh ### BEGIN INIT INFO # Provides: lighttpd # Required-Start: networking # Required-Stop: networking # Default-Start: 2 3 4 5 # Default-Stop: 0 1 6 # Short-Description: Start the lighttpd web server. ### END INIT INFO PATH=/sbin:/bin:/usr/sbin:/usr/bin DAEMON=/usr/sbin/lighttpd NAME=lighttpd DESC="web server" PIDFILE=/var/run/$NAME.pid SCRIPTNAME=/etc/init.d/$NAME ENV="env -i LANG=C PATH=/usr/local/bin:/usr/bin:/bin" SSD="/sbin/start-stop-daemon" DAEMON_OPTS="-f /etc/lighttpd/lighttpd.conf" test -x $DAEMON || exit 0 set -e # be sure there is a /var/run/lighttpd, even with tmpfs mkdir -p /var/run/lighttpd > /dev/null 2> /dev/null chown www-data:www-data /var/run/lighttpd chmod 0750 /var/run/lighttpd . /lib/lsb/init-functions case "$1" in start) log_daemon_msg "Starting $DESC" $NAME if ! $ENV $SSD --start --quiet\ --pidfile $PIDFILE --exec $DAEMON -- $DAEMON_OPTS ; then log_end_msg 1 else log_end_msg 0 fi ;; stop) log_daemon_msg "Stopping $DESC" $NAME if $SSD --quiet --stop --oknodo --retry 30\ --pidfile $PIDFILE --exec $DAEMON; then rm -f $PIDFILE log_end_msg 0 else log_end_msg 1 fi ;; reload) log_daemon_msg "Reloading $DESC configuration" $NAME if $SSD --stop --signal 2 --oknodo --retry 30\ --quiet --pidfile $PIDFILE --exec $DAEMON; then if $ENV $SSD --start --quiet \ --pidfile $PIDFILE --exec $DAEMON -- $DAEMON_OPTS ; then log_end_msg 0 else log_end_msg 1 fi else log_end_msg 1 fi ;; restart|force-reload) $0 stop [ -r $PIDFILE ] && while pidof lighttpd |\ grep -q `cat $PIDFILE 2>/dev/null` 2>/dev/null ; do sleep 1; done $0 start ;; *) echo "Usage: $SCRIPTNAME {start|stop|restart|reload|force-reload}" >&2 exit 1 ;; esac exit 0

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  • How to prioritize openvpn traffic?

    - by aditsu
    I have an openvpn server, with one network interface. VPN traffic is extremely slow. I tried to do traffic control with this configuration (currently): qdisc del dev eth0 root qdisc add dev eth0 root handle 1: htb default 12 class add dev eth0 parent 1: classid 1:1 htb rate 900mbit #vpn class add dev eth0 parent 1:1 classid 1:10 htb rate 1500kbit ceil 3000kbit prio 1 #local net class add dev eth0 parent 1:1 classid 1:11 htb rate 10mbit ceil 900mbit prio 2 #other class add dev eth0 parent 1:1 classid 1:12 htb rate 500kbit ceil 1000kbit prio 2 filter add dev eth0 protocol ip parent 1:0 prio 1 u32 match ip sport 1194 0xffff flowid 1:10 filter add dev eth0 protocol ip parent 1:0 prio 2 u32 match ip dst 192.168.10.0/24 flowid 1:11 qdisc add dev eth0 parent 1:10 handle 10: sfq perturb 10 qdisc add dev eth0 parent 1:11 handle 11: sfq perturb 10 qdisc add dev eth0 parent 1:12 handle 12: sfq perturb 10 But it's still extremely slow. I have an imaps connection that keeps transferring data continuously (I successfully limited the rate) but with openvpn I can't seem to get more than about 100kbit/s The internet connection speed is about 3mbit/s (symmetric) What could be the problem? Does the sport filter work for udp?

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  • when to set up a mail server?

    - by ajsie
    i've got a web service up and running with apache on ubuntu server in a vps from a hosting company (long sentence:)). i wonder when someone would like to set up a own mail server (postfix + dovecot)? cause i just want to be able to: send emails (account activation etc) to my users with php - the emails have to appear to come from the website's domain receive emails from my users (customer support etc) using Apple Mail/Microsoft Outlook. could this be accomplished with an email hosting company? are there situations i would benefit from setting up an own mail server on ubuntu?

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  • redirect temporarily STDOUT to another file descriptor, but still to screen

    - by Carlos Campderrós
    I'm making a script that executes some commands inside, and these commands show some output on STDOUT (and STDERR as well, but that's no problem). I need that my script generates a .tar.gz file to STDOUT, so the output of some commands executed in the script also go to STDOUT and this ends with a not valid .tar.gz file in the output. So, in short, it's possible to output the first commands to the screen (as I still want to see the output) but not via STDOUT? Also I would like to keep the STDERR untouched so only error messages appear there. A simple example of what I mean. This would be my script: #!/bin/bash # the output of these commands shouldn't go to STDOUT, but still appear on screen some_cmd foo bar other_cmd baz #the following command creates a tar.gz of the "whatever" folder, #and outputs the result to STDOUT tar zc whatever/ I've tried messing with exec and the file descriptors, but I still can't get it to work: #!/bin/bash # save STDOUT to #3 exec 3>&1 # the output of these commands should go to #3 and screen, but not STDOUT some_cmd foo bar other_cmd baz # restore STDOUT exec 1>&3 # the output of this command should be the only one that goes to STDOUT tar zc whatever/ I guess I'm lacking closing STDOUT after the first exec and reopen it again or something, but I can't find the right way to do it (right now the result is the same as if I didn't add the execs

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  • Getting rid of Plesk on a VPS

    - by TomA
    I've been using a relatively expensive VPS for hosting about 30 domains and I want to migrate to a cheaper one, without Plesk. Both use CentOS. My users will not care, they don't use Plesk anyway. But I will not be able to use it for creating new virtual hosts, FTP accounts etc. I'm not a commandline guru, esp. not in a server environment. Is there a free Plesk alternative for these purposes? I need to: Create a new virtual host with it's own FTP account Setup some basic FTP quota I don't need: DNS management (the new VPS service has an external DNS management GUI) Mail server management (I use Google Apps) Any suggestions welcome, from Plesk alternatives to "RTFM" or links to tutorials.

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  • Is there a max thread per mongrel?

    - by Blankman
    I don't know much about ruby, much less how or what is involved with hosting a ruby on rails web app. BUT, I recall hearing someone saying that they have to run multiple mongrels b/c of a limit of 50 threads? Is this true (or something similiar)? Why does it have this limitation?

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  • /etc/inputrc does not seem to be recognized as user on Ubuntu 8.04.2 LTS

    - by Brian Hogg
    On a new installation of Ubuntu 8.04.2 LTS, logging in as a standard user does not maintain the keybindings (whether through sudo su - or direct from ssh). As the root user everything is fine and /root/.inputrc does not exist (only /etc/inputrc) which has its default settings. In addition setting a ~/.bashrc and ~/.profile to the same as the root user (and chown'ing to user:user) has no effect. Am I missing something here?

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  • Ubuntu dpkg error , after crash and filesystem error recovery

    - by Radian
    Ubuntu recently crashed , causing it's partition damaged ( which is EXT4) and Ubuntu was unable to boot , because it couldn't mount anything , only displays Busybox So I used the Live CD to run fsck on the partition, which fixed it , but deleted some nodes Now Ubuntu is working , but some files were missing , for example I lost the Panels configurations and Chromium's Extensions The Most Annoying problem , that there is some files corrupted , for example when I try to install any program, I got this (Reading database ... 95%dpkg: unrecoverable fatal error, aborting: files list file for package 'libservlet2.4-java' is missing final newline I tried these commands dpkg --configure -a apt-get -f install and from GUI , Synaptic Package Manager Fix Broken Packages So this file "libservlet2.4-java" Does anyone knows what it does ! and where it's location ? and how can I fix/get-correct-version-of it ? Also , is there any way I could tell Ubuntu to Check for ALL it's file , and if there is something corrupted it should recover it form the CD ?

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  • Bash Script to Back Up Backs Up Itself

    - by Jay LaCroix
    I have the following bash script that creates a tar.gz of my filesystem on a Kubuntu PC. The problem is, that it also tries to backup the tar.gz backup file, even though I am storing the backup in /tmp and omitting /tmp from the backup. I am wondering why it's backing up the file in /tmp even though I told it not to. #!/bin/bash # init DATE=$(date +20%y%m%d) sudo tar -cvpzf /tmp/`hostname`_$DATE.tar.gz \ --exclude=/proc \ --exclude=/lost+found \ --exclude=/sys \ --exclude=/mnt \ --exclude=/media \ --exclude=/dev \ --exclude=/tmp \ --exclude=/home/jlacroix/Desktop \ --exclude=/home/jlacroix/Documents \ --exclude=/home/jlacroix/Music \ --exclude=/home/jlacroix/Pictures \ --exclude=/home/jlacroix/Projects \ --exclude=/home/jlacroix/Roms \ --exclude=/home/jlacroix/Videos \ --exclude=/home/jlacroix/.VirtualBox\ VMs \ --exclude=/home/jlacroix/.SpiderOak \ / scp /tmp/`hostname`_$DATE.tar.gz jlacroix@Pluto:/share/Recovery/Snapshots sudo rm /tmp/`hostname`_$DATE.tar.gz

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  • FTP User cannot modify files but has correct permissions

    - by Lothar_Grimpsenbacher
    I have created a new user (foo) and when he logs in via ftp he cannot edit the files in the directory to which he has access. In the directory he can log into ls -l gives me: -rw-rw-r-- 1 root www-pub 6427 Nov 17 04:21 index.html The user belongs to the group www-pub. Here is the output of cat /etc/group to demonstrate that he is indeed in that group: ... www-pub:x:1001:ftpuser,www-data,foo foo:x:1002: *edit the permissions on the containing directory are: drwxrwsr-x 5 root www-pub 4096 Nov 17 02:53 thecontainingdir and the one above that: drwxrwsr-x 49 root www-pub 4096 Nov 16 02:40 thenextdirup So since he can log in via ftp and since the file he needs to edit has the correct permissions to let the group www-pub read and write the file and he is a member of that group, why can't he edit it (or upload anything)? Only when I change the file to 777 can he edit it. It's as if he's NOT in the group... but he is! What's going on?

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  • Bluetooth not seeing mouse (Fedora)

    - by Chris
    I have a Lenovo S10 'netbook' that I've installed Fedora 17 ("LXDE spin") on. So far pretty much everything works great, except, the on-board Bluetooth. lsusb shows the controller present (0a5c:2101 Broadcom Corp. Bluetooth Controller), hcitool dev shows hci0 present, but when I put my mouse ("Lenovo Bluetooth Laser Mouse," which works perfectly paired with a MacBook Pro, MacBook Air, Mac mini, and Lenovo SL500 (with a USB dongle; running Windows 7)) into pairing mode and run hcitool scan (reports "Scanning ..." and, without further information or error message, returns to the shell prompt), blueman-manager, or bluetooth-wizard (from the gnome-bluetooth package) and try to detect the mouse, I get nothing... Frustrating! Thanks anyone who can point me in the right direction!

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  • 2 drives, slow software RAID1 (md)

    - by bart613
    Hello, I've got a server from hetzner.de (EQ4) with 2* SAMSUNG HD753LJ drives (750G 32MB cache). OS is CentOS 5 (x86_64). Drives are combined together into two RAID1 partitions: /dev/md0 which is 512MB big and has only /boot partitions /dev/md1 which is over 700GB big and is one big LVM which hosts other partitions Now, I've been running some benchmarks and it seems like even though exactly the same drives, speed differs a bit on each of them. # hdparm -tT /dev/sda /dev/sda: Timing cached reads: 25612 MB in 1.99 seconds = 12860.70 MB/sec Timing buffered disk reads: 352 MB in 3.01 seconds = 116.80 MB/sec # hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 25524 MB in 1.99 seconds = 12815.99 MB/sec Timing buffered disk reads: 342 MB in 3.01 seconds = 113.64 MB/sec Also, when I run eg. pgbench which is stressing IO quite heavily, I can see following from iostat output: Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sda 0.00 231.40 0.00 298.00 0.00 9683.20 32.49 0.17 0.58 0.34 10.24 sda1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sda2 0.00 231.40 0.00 298.00 0.00 9683.20 32.49 0.17 0.58 0.34 10.24 sdb 0.00 231.40 0.00 301.80 0.00 9740.80 32.28 14.19 51.17 3.10 93.68 sdb1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sdb2 0.00 231.40 0.00 301.80 0.00 9740.80 32.28 14.19 51.17 3.10 93.68 md1 0.00 0.00 0.00 529.60 0.00 9692.80 18.30 0.00 0.00 0.00 0.00 md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-0 0.00 0.00 0.00 0.60 0.00 4.80 8.00 0.00 0.00 0.00 0.00 dm-1 0.00 0.00 0.00 529.00 0.00 9688.00 18.31 24.51 49.91 1.81 95.92 Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sda 0.00 152.40 0.00 330.60 0.00 5176.00 15.66 0.19 0.57 0.19 6.24 sda1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sda2 0.00 152.40 0.00 330.60 0.00 5176.00 15.66 0.19 0.57 0.19 6.24 sdb 0.00 152.40 0.00 326.20 0.00 5118.40 15.69 19.96 55.36 3.01 98.16 sdb1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sdb2 0.00 152.40 0.00 326.20 0.00 5118.40 15.69 19.96 55.36 3.01 98.16 md1 0.00 0.00 0.00 482.80 0.00 5166.40 10.70 0.00 0.00 0.00 0.00 md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-1 0.00 0.00 0.00 482.80 0.00 5166.40 10.70 30.19 56.92 2.05 99.04 Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sda 0.00 181.64 0.00 324.55 0.00 5445.11 16.78 0.15 0.45 0.21 6.87 sda1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sda2 0.00 181.64 0.00 324.55 0.00 5445.11 16.78 0.15 0.45 0.21 6.87 sdb 0.00 181.84 0.00 328.54 0.00 5493.01 16.72 18.34 61.57 3.01 99.00 sdb1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sdb2 0.00 181.84 0.00 328.54 0.00 5493.01 16.72 18.34 61.57 3.01 99.00 md1 0.00 0.00 0.00 506.39 0.00 5477.05 10.82 0.00 0.00 0.00 0.00 md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-1 0.00 0.00 0.00 506.39 0.00 5477.05 10.82 28.77 62.15 1.96 99.00 And this is completely getting me confused. How come two exactly the same specced drives have such a difference in write speed (see util%)? I haven't really paid attention to those speeds before, so perhaps that something normal -- if someone could confirm I would be really grateful. Otherwise, if someone have seen such behavior again or knows what is causing such behavior I would really appreciate answer. I'll also add that both "smartctl -a" and "hdparm -I" output are exactly the same and are not indicating any hardware problems. The slower drive was changed already two times (to new ones). Also I asked to change the drives with places, and then sda were slower and sdb quicker (so the slow one was the same drive). SATA cables were changed two times already.

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  • Millions of SYN_RECV connections, no DDoS

    - by ThomK
    We have such server structure: reverse proxy (nginx) - worker (uwsgi) - postgresql / memcached. All servers are in local network behind router, with NATed external ip:ports (http/s 80/443 to proxy, and ssh 22 to all servers). Problem is, that sometimes proxy server netstat reports MILLIONS of SYN_RECV connections. From same IP / same ports. Like that: nginx ~ # netstat -n | grep 83.238.153.195 tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV [...] And this is not DDoS, because all IPs affected belongs to our website users. On side note, users says that it's not affecting them. Website is online and working, but... that particular one (from example above) told me that website is down and Firefox can't connect. I've done tcpdump. 19:42:14.826011 IP 83.238.153.195.zephyr-srv > 192.168.1.1.http: Flags [S], seq 1845850583, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:14.826042 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:17.887331 IP 83.238.153.195.zephyr-srv > 192.168.1.1.http: Flags [S], seq 1845850583, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:17.887343 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:19.065497 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:23.918064 IP 83.238.153.195.zephyr-srv > 192.168.1.1.http: Flags [S], seq 1845850583, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:23.918076 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:25.265499 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:37.265501 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:37.758051 IP 83.238.153.195.2107 > 192.168.1.1.http: Flags [S], seq 564208067, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:37.758069 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:40.714360 IP 83.238.153.195.2107 > 192.168.1.1.http: Flags [S], seq 564208067, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:40.714374 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:41.665503 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:46.751073 IP 83.238.153.195.2107 > 192.168.1.1.http: Flags [S], seq 564208067, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:46.751087 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:47.665498 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:59.865499 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:01.265500 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:13.320382 IP 83.238.153.195.2114 > 192.168.1.1.http: Flags [S], seq 2136055006, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:13.320399 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:16.320556 IP 83.238.153.195.2114 > 192.168.1.1.http: Flags [S], seq 2136055006, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:16.320569 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:17.665498 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:22.250069 IP 83.238.153.195.2114 > 192.168.1.1.http: Flags [S], seq 2136055006, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:22.250080 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:23.665500 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:23.865501 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:35.665498 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:37.903038 IP 83.238.153.195.2213 > 192.168.1.1.http: Flags [S], seq 2918118729, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:37.903054 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:40.772899 IP 83.238.153.195.2213 > 192.168.1.1.http: Flags [S], seq 2918118729, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:40.772912 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:41.865500 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:46.793057 IP 83.238.153.195.2213 > 192.168.1.1.http: Flags [S], seq 2918118729, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:46.793069 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:47.865500 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:49.465503 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 Anyone have some thoughts on that?

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