Search Results

Search found 138 results on 6 pages for 'stripe'.

Page 2/6 | < Previous Page | 1 2 3 4 5 6  | Next Page >

  • dd oflag=direct 5x fast

    - by César
    I have Centos 6.2 in server with this specs: 2xCPU 16 Core AMD Opteron 6282 SE 64GB RAM Raid controller H700 1GB cache NV - 2HD 74GB SAS 15Krpm RAID1 stripe 16k (OS Centos 6.2) sda - 4HD 146GB SAS 15Krpm RAID10 stripe 16k (ext4 bs 4096, no barriers) sdb -> /vol01 Raid controller H800 1GB cache nv - MD1200 12HD 300GB SAS 15Krpm RAID10 stripe 256k (For DB Postgres 8.3.18) (ext4 bs 4096, stride 64, stripe-width 384, no barriers) sdc -> /vol02 I'm benchmarking IO speed with dd, and view thah if in RAID10 12 disk exec: dd if=/dev/zero of=DD bs=8M count=10000 oflag=direct 10000+0 records in 10000+0 records out 83886080000 bytes (84 GB) copied, 126,03 s, 666 MB/s but if I remove "oflag=direct" option obtain about 80 MB/s. In read benchmark, results are similar: dd of=/dev/null if=DD bs=8M count=10000 iflag=direct 10000+0 records in 10000+0 records out 83886080000 bytes (84 GB) copied, 79,5918 s, 1,1 GB/s If remove iflag=direct obtain 150MB/s... I don't understand this huge differences, on other machines y don't have this behavior. Can I have some kernel parameter misconfigured? Thanks!

    Read the article

  • linux hardware raid 10 / lvm / virtual machine partition alignment and filesystem optimization

    - by Jason Ward
    I've been reading everything I can find about partition alignment and filesystem optimization (ext4 and xfs) but still don't know enough to be confident in setting up my current configuration. My remaining confusion comes from the LVM layer and if I should use raid parameters on the filesystem in guest os'es. My main questions are: When I use 'pvcreate --dataalignment' do I use the stripe-width as calculated for a filesystem on RAID (128kB for ext4 in my situation), the Stripe size of the RAID set (256kB), something else altogether, or do I not need this? When I create ext2/3/4 or xfs filesystems in guests on the Logical Volumes, should I add the settings for the underlying RAID (e.g. mkfs.ext4 -b 4096 -E stride=64,stripe-width=128)? Does anyone see any glaring errors in my set up below? I'm running some benchmarks now but haven't done enough to start comparing results. I have four drives in RAID 10 on a 3ware 9750-4i controller (more details on the settings below) giving me a 6.0TB device at /dev/sda. Here is my partition table: Model: LSI 9750-4i DISK (scsi) Disk /dev/sda: 5722024MiB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1.00MiB 257MiB 256MiB ext4 BOOTPART boot 2 257MiB 4353MiB 4096MiB linux-swap(v1) 3 4353MiB 266497MiB 262144MiB ext4 4 266497MiB 4460801MiB 4194304MiB Partition 1 is to be the /boot partition for my xen host. Partition 2 is swap. Partition 3 is to be the root (/) for my xen host. Partition 4 is to be (the only) physical volume to be used by LVM (for those who are counting, I left about 1.2TB unallocated for now) For my Xen guests, I usually create a Logical Volume of the needed size and present it to the guests for them to partition as needed. I know there are other ways of handling that but this method works best for my situation. Here's the hardware of interest on my CentOS 6.3 Xen Host: 4x Seagate Barracuda 3TB ST3000DM001 Drives (sector size: 512 logical/4096 physical) 3ware 9750-4i w/BBU (sector size reported: 512 logical/512 physical) All four drives make up a RAID 10 array. Stripe: 256kB Write Cache enabled Read Cache: intelligent StoreSave: Balance Thanks!

    Read the article

  • Black screen with thinkpad edge e525, AMD radeon HD before and after installation, plymouth?

    - by carolien
    I have a new thinkpad edge e525 (which should work) and wanted to try ubuntu (first linux experience). With the ubuntu desktop-cd I had a blackscreen before installation, I could fix that with nomodeset. After the installation, when rebooting I got the black screen again. First I see some ubuntu colour with a green busted stripe. I have the same problem with the live boot, also tried mint live, the stripe gets pink. I installed xubuntu 64bit from an alternate cd and I didnt have problems until de reboot after the installation. Same problem, just a black screen with the green stripe than blackscreen. I tried several things: adding nomodeset to the bootmenu, but than I get: No connection to plymouth and it is stuck at checking the battery status. I tried to replace quiet splash with text. Didnt work either. actually one time I saw a blue booting image before that. I managed to get a root command though via the recovery boot. I didnt dare to just remove the plymouth package. Can I just delete plymouth or do I have to deinstall it as described in several ways. (Problem is, right now the notebook doesnt have a internet connection. And I dont know how to manage it with a usb stick?) Or do I have to install the AMD catalyst driver manually? (Again, how can I do that with an usb stick) I also tried this: Ubuntu hits a black screen after boot. Is there any solution without internet? And if I need internet which is the right one? Please explain step by step what I have to write and so on! Thank you! also tried: set gfxpayload=text and: just remove splash and adding vesafb.nonsense=1 to the grub editor, because I couldnt find it anywhere

    Read the article

  • how to reapply knockout binding

    - by MikeW
    Currently I have a knockout binding that stripes rows in a list which works fine ko.bindingHandlers.stripe = { update: function (element, valueAccessor, allBindingsAccessor) { var value = ko.utils.unwrapObservable(valueAccessor()); //creates the dependency var allBindings = allBindingsAccessor(); var even = allBindings.evenClass; var odd = allBindings.oddClass; //update odd rows $(element).children(":nth-child(odd)").addClass(odd).removeClass(even); //update even rows $(element).children(":nth-child(even)").addClass(even).removeClass(odd); ; } } Triggered from <button data-bind="click: addWidget" style="display:none">Add Item</button> The problem I have is when reloading data from the server , I call addWidget() manually in the view model the stripe binding handler is not applied - all rows appear as same color, if I click the html button then the binding happens and stripes appear var ViewModel = function() { self.addWidget(); }); Is it possible to reapply this custom binding manually in js? Thanks Edit: The stripe binding gets applied like so <div data-bind="foreach: widgets, stripe: widgets, evenClass: 'light', oddClass: 'dark'">

    Read the article

  • Making fdisk see software RAID 0

    - by unknownthreat
    I am following http://grub.enbug.org/Grub2LiveCdInstallGuide and I am using software RAID 0. I am using Ubuntu 10.10 LiveCD and is trying to restore grub2 after installing Windows 7 in another partition. Here is the console's outputs: ubuntu@ubuntu:~$ sudo fdisk -l Unable to seek on /dev/sad ubuntu@ubuntu:~$ sudo dmraid -r /dev/sdb: nvidia, "nvidia_acajefec", stripe, ok, 488397166 sectors, data@ 0 /dev/sda: nvidia, "nvidia_acajefec", stripe, ok, 488397166 sectors, data@ 0 So do you have an idea for how to make fdisk see my RAID array? How to make fdisk detect the Software RAID like dmraid?

    Read the article

  • converting 0+1 raid array to 0

    - by werelord
    I'm currently running raid 0+1; four 500 GB drives in the array.. I'm looking at migrating the array from 0+1 (Stripe+Mirror) to 0 only (stripe).. The goal is to remove the hard drives from the array in order to put them in the newly purchased Drobo, then copy the data from the remaining striped raid to the said Drobo.. Is it sufficient to just remove the drives themselves and change the raid configuration within the nvidia raid config?? Or is there something more that needs to be done?? Does the order matter (i.e. removing drives first or changing the raid configuration??) Is it possible to migrate the array this way without having any loss of data? I'm wary about burning all that data to DVDs (few hundred GB worth) to back it up.. Any other advice from people that may have done this (or have other insight) would be helpful as well..

    Read the article

  • Restoring GRUB2 on Software RAID 0 after Windows 7 wiped it using Ubuntu 10.10 LiveCD

    - by unknownthreat
    I have installed Ubuntu 10.10 on my system. However, I need to install Windows 7 back, and I expect that it would alter GRUB and it did. Right now, my partition on my Software RAID 0 looks like this: nvidia_acajefec1 is Ubuntu 10.10 and nvidia_acajefec3 is Windows 7. I've been following some guides around and I am always stuck at GRUB not able to detect the usual RAID content. I've tried running: sudo grub > root (hd0,0) GRUB complains it couldn't find my hard disk. So I tried: find (hd0,0) And it complains that it couldn't find anything. So I tried: find /boot/grub/stage1 It said "file not found". Here's the text from the console: ubuntu@ubuntu:~$ grub Probing devices to guess BIOS drives. This may take a long time. [ Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists the possible completions of a device/filename. ] grub> root (hd0,0) root (hd0,0) Error 21: Selected disk does not exist grub> find /boot/grub/stage1 find /boot/grub/stage1 Error 15: File not found Fortunately, I got one person suggesting that what I've been trying to do is for GRUB Legacy, not GRUB2. So I went to the suggested website, ** (http://grub.enbug.org/Grub2LiveCdInstallGuide) **try to look around, and try: ubuntu@ubuntu:~$ sudo fdisk -l Unable to seek on /dev/sda This is just the step 2 of the instruction in the http://grub.enbug.org/Grub2LiveCdInstallGuide and I cannot proceed because it cannot seek /dev/sda. However, ubuntu@ubuntu:~$ sudo dmraid -r /dev/sdb: nvidia, "nvidia_acajefec", stripe, ok, 488397166 sectors, data@ 0 /dev/sda: nvidia, "nvidia_acajefec", stripe, ok, 488397166 sectors, data@ 0 So what now? Do you have an idea for how to make fdisk see my RAID array on live cd (Ubuntu 10.10)? Honestly, I am lost, very lost in trying to restore GRUB2 on this software RAID 0 system right now.

    Read the article

  • usb wifi dongle on ubuntu server, cannot install realtek driver RTL 8188cus

    - by Sandro Dzneladze
    I got cheap Ebay wifi dongle from HongKong, Im trying to set it up on my ubuntu server. Occasionally need to move server, so it cannot always be connected to router via lan. Anyhow, usb wifi came with a driver cd. I uploaded files to my home directory and tried to run install script (RTL 8188cus): sudo bash install.sh But I get error: Authentication requested [root] for make driver: make ARCH=x86_64 CROSS_COMPILE= -C /lib/modules/2.6.38-8-server/build M=/home/minime/RTL 8188cus/Linux/driver/rtl8192CU_linux_v2.0.1324.20110126 modules make[1]: Entering directory `/usr/src/linux-headers-2.6.38-8-server' make[1]: *** No rule to make target `8188cus/Linux/driver/rtl8192CU_linux_v2.0.1324.20110126'. Stop. make[1]: Leaving directory `/usr/src/linux-headers-2.6.38-8-server' make: *** [modules] Error 2 Compile make driver error: 2, Please check error Mesg Any ideas what Im doing wrong? There is another driver folder for linux called: RTL 81XX, which doesn't have install.sh at all! I tried to use make command, but I get: make: *** No targets specified and no makefile found. Stop. Any help? this is first time I'm installing driver from source. Im on Ubuntu 11.04 server. lsusb Bus 001 Device 002: ID 0bda:8176 Realtek Semiconductor Corp. lspci -nn 00:00.0 Host bridge [0600]: Intel Corporation N10 Family DMI Bridge [8086:a000] (rev 02) 00:02.0 VGA compatible controller [0300]: Intel Corporation N10 Family Integrated Graphics Controller [8086:a001] (rev 02) 00:1b.0 Audio device [0403]: Intel Corporation N10/ICH 7 Family High Definition Audio Controller [8086:27d8] (rev 02) 00:1c.0 PCI bridge [0604]: Intel Corporation N10/ICH 7 Family PCI Express Port 1 [8086:27d0] (rev 02) 00:1d.0 USB Controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #1 [8086:27c8] (rev 02) 00:1d.1 USB Controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 [8086:27c9] (rev 02) 00:1d.2 USB Controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 [8086:27ca] (rev 02) 00:1d.3 USB Controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 [8086:27cb] (rev 02) 00:1d.7 USB Controller [0c03]: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller [8086:27cc] (rev 02) 00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev e2) 00:1f.0 ISA bridge [0601]: Intel Corporation NM10 Family LPC Controller [8086:27bc] (rev 02) 00:1f.2 IDE interface [0101]: Intel Corporation N10/ICH7 Family SATA IDE Controller [8086:27c0] (rev 02) 00:1f.3 SMBus [0c05]: Intel Corporation N10/ICH 7 Family SMBus Controller [8086:27da] (rev 02) 01:00.0 Ethernet controller [0200]: Atheros Communications Device [1969:1083] (rev c0) sudo lshw description: Desktop Computer product: To Be Filled By O.E.M. (To Be Filled By O.E.M.) vendor: To Be Filled By O.E.M. version: To Be Filled By O.E.M. serial: To Be Filled By O.E.M. width: 64 bits capabilities: smbios-2.6 dmi-2.6 vsyscall64 vsyscall32 configuration: boot=normal chassis=desktop family=To Be Filled By O.E.M. sku=To Be Filled By O.E.M. uuid=00020003-0004-0005-0006-000700080009 *-core description: Motherboard product: AD525PV3 vendor: ASRock physical id: 0 *-firmware description: BIOS vendor: American Megatrends Inc. physical id: 0 version: P1.20 date: 04/01/2011 size: 64KiB capacity: 448KiB capabilities: pci upgrade shadowing cdboot bootselect socketedrom edd int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard int14serial int17printer int10video acpi usb ls120boot zipboot biosbootspecification netboot *-cpu description: CPU product: Intel(R) Atom(TM) CPU D525 @ 1.80GHz vendor: Intel Corp. physical id: 4 bus info: cpu@0 version: Intel(R) Atom(TM) CPU D525 @ 1.80GHz serial: To Be Filled By O.E.M. slot: CPUSocket size: 1800MHz capacity: 1800MHz width: 64 bits clock: 200MHz capabilities: x86-64 fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl tm2 ssse3 cx16 xtpr pdcm movbe lahf_lm configuration: cores=2 enabledcores=2 threads=4 *-cache:0 description: L1 cache physical id: 5 slot: L1-Cache size: 48KiB capacity: 48KiB capabilities: internal write-back data *-cache:1 description: L2 cache physical id: 6 slot: L2-Cache size: 1MiB capacity: 1MiB capabilities: internal write-back unified *-memory description: System Memory physical id: c slot: System board or motherboard size: 2GiB *-bank:0 description: SODIMM DDR2 Synchronous 800 MHz (1.2 ns) product: ModulePartNumber00 vendor: Manufacturer00 physical id: 0 serial: SerNum00 slot: DIMM0 size: 2GiB width: 64 bits clock: 800MHz (1.2ns) *-bank:1 description: DIMM [empty] product: ModulePartNumber01 vendor: Manufacturer01 physical id: 1 serial: SerNum01 slot: DIMM1 *-pci description: Host bridge product: N10 Family DMI Bridge vendor: Intel Corporation physical id: 100 bus info: pci@0000:00:00.0 version: 02 width: 32 bits clock: 33MHz configuration: driver=agpgart-intel resources: irq:0 *-display description: VGA compatible controller product: N10 Family Integrated Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 02 width: 32 bits clock: 33MHz capabilities: msi pm vga_controller bus_master cap_list rom configuration: driver=i915 latency=0 resources: irq:41 memory:fea80000-feafffff ioport:dc00(size=8) memory:e0000000-efffffff memory:fe900000-fe9fffff *-multimedia description: Audio device product: N10/ICH 7 Family High Definition Audio Controller vendor: Intel Corporation physical id: 1b bus info: pci@0000:00:1b.0 version: 02 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list configuration: driver=HDA Intel latency=0 resources: irq:43 memory:fea78000-fea7bfff *-pci:0 description: PCI bridge product: N10/ICH 7 Family PCI Express Port 1 vendor: Intel Corporation physical id: 1c bus info: pci@0000:00:1c.0 version: 02 width: 32 bits clock: 33MHz capabilities: pci pciexpress msi pm normal_decode bus_master cap_list configuration: driver=pcieport resources: irq:40 ioport:e000(size=4096) memory:feb00000-febfffff ioport:80000000(size=2097152) *-network description: Ethernet interface product: Atheros Communications vendor: Atheros Communications physical id: 0 bus info: pci@0000:01:00.0 logical name: eth0 version: c0 serial: XX size: 100Mbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress vpd bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=atl1c driverversion=1.0.1.0-NAPI duplex=full firmware=N/A ip=192.168.1.99 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s resources: irq:42 memory:febc0000-febfffff ioport:ec00(size=128) *-usb:0 description: USB Controller product: N10/ICH 7 Family USB UHCI Controller #1 vendor: Intel Corporation physical id: 1d bus info: pci@0000:00:1d.0 version: 02 width: 32 bits clock: 33MHz capabilities: uhci bus_master configuration: driver=uhci_hcd latency=0 resources: irq:23 ioport:d880(size=32) *-usb:1 description: USB Controller product: N10/ICH 7 Family USB UHCI Controller #2 vendor: Intel Corporation physical id: 1d.1 bus info: pci@0000:00:1d.1 version: 02 width: 32 bits clock: 33MHz capabilities: uhci bus_master configuration: driver=uhci_hcd latency=0 resources: irq:19 ioport:d800(size=32) *-usb:2 description: USB Controller product: N10/ICH 7 Family USB UHCI Controller #3 vendor: Intel Corporation physical id: 1d.2 bus info: pci@0000:00:1d.2 version: 02 width: 32 bits clock: 33MHz capabilities: uhci bus_master configuration: driver=uhci_hcd latency=0 resources: irq:18 ioport:d480(size=32) *-usb:3 description: USB Controller product: N10/ICH 7 Family USB UHCI Controller #4 vendor: Intel Corporation physical id: 1d.3 bus info: pci@0000:00:1d.3 version: 02 width: 32 bits clock: 33MHz capabilities: uhci bus_master configuration: driver=uhci_hcd latency=0 resources: irq:16 ioport:d400(size=32) *-usb:4 description: USB Controller product: N10/ICH 7 Family USB2 EHCI Controller vendor: Intel Corporation physical id: 1d.7 bus info: pci@0000:00:1d.7 version: 02 width: 32 bits clock: 33MHz capabilities: pm debug ehci bus_master cap_list configuration: driver=ehci_hcd latency=0 resources: irq:23 memory:fea77c00-fea77fff *-pci:1 description: PCI bridge product: 82801 Mobile PCI Bridge vendor: Intel Corporation physical id: 1e bus info: pci@0000:00:1e.0 version: e2 width: 32 bits clock: 33MHz capabilities: pci subtractive_decode bus_master cap_list *-isa description: ISA bridge product: NM10 Family LPC Controller vendor: Intel Corporation physical id: 1f bus info: pci@0000:00:1f.0 version: 02 width: 32 bits clock: 33MHz capabilities: isa bus_master cap_list configuration: latency=0 *-ide description: IDE interface product: N10/ICH7 Family SATA IDE Controller vendor: Intel Corporation physical id: 1f.2 bus info: pci@0000:00:1f.2 logical name: scsi0 version: 02 width: 32 bits clock: 66MHz capabilities: ide pm bus_master cap_list emulated configuration: driver=ata_piix latency=0 resources: irq:19 ioport:1f0(size=8) ioport:3f6 ioport:170(size=8) ioport:376 ioport:ff90(size=16) memory:80200000-802003ff *-disk description: ATA Disk product: WDC WD10TPVT-11U vendor: Western Digital physical id: 0.0.0 bus info: scsi@0:0.0.0 logical name: /dev/sda version: 01.0 serial: WD-WXC1A80P0314 size: 931GiB (1TB) capabilities: partitioned partitioned:dos configuration: ansiversion=5 signature=00088c47 *-volume:0 description: EXT4 volume vendor: Linux physical id: 1 bus info: scsi@0:0.0.0,1 logical name: /dev/sda1 logical name: /media/private version: 1.0 serial: 042daf2d-350c-4640-a76a-4554c9d98c59 size: 300GiB capacity: 300GiB capabilities: primary journaled extended_attributes large_files huge_files dir_nlink recover extents ext4 ext2 initialized configuration: created=2011-11-06 11:05:03 filesystem=ext4 label=Private lastmountpoint=/media/private modified=2012-04-13 20:01:16 mount.fstype=ext4 mount.options=rw,relatime,barrier=1,stripe=1,data=ordered mounted=2012-04-13 20:01:16 state=mounted *-volume:1 description: Extended partition physical id: 2 bus info: scsi@0:0.0.0,2 logical name: /dev/sda2 size: 625GiB capacity: 625GiB capabilities: primary extended partitioned partitioned:extended *-logicalvolume:0 description: Linux filesystem partition physical id: 5 logical name: /dev/sda5 logical name: /media/storage capacity: 600GiB configuration: mount.fstype=ext4 mount.options=rw,relatime,barrier=1,stripe=1,data=ordered state=mounted *-logicalvolume:1 description: Linux filesystem partition physical id: 6 logical name: /dev/sda6 logical name: /media/dropbox capacity: 24GiB configuration: mount.fstype=ext4 mount.options=rw,relatime,barrier=1,stripe=1,data=ordered state=mounted *-volume:2 description: EXT4 volume vendor: Linux physical id: 3 bus info: scsi@0:0.0.0,3 logical name: /dev/sda3 logical name: /media/www version: 1.0 serial: 9b0a27b4-05d8-40d5-bfc7-4aeba198db7b size: 2570MiB capacity: 2570MiB capabilities: primary journaled extended_attributes large_files huge_files dir_nlink recover extents ext4 ext2 initialized configuration: created=2011-11-06 11:05:11 filesystem=ext4 label=www lastmountpoint=/media/www modified=2012-04-15 11:31:12 mount.fstype=ext4 mount.options=rw,relatime,barrier=1,stripe=1,data=ordered mounted=2012-04-15 11:31:12 state=mounted *-volume:3 description: Linux swap volume physical id: 4 bus info: scsi@0:0.0.0,4 logical name: /dev/sda4 version: 1 serial: 6ed1130e-3aad-4fa6-890b-77e729121e3b size: 4098MiB capacity: 4098MiB capabilities: primary nofs swap initialized configuration: filesystem=swap pagesize=4096 *-serial UNCLAIMED description: SMBus product: N10/ICH 7 Family SMBus Controller vendor: Intel Corporation physical id: 1f.3 bus info: pci@0000:00:1f.3 version: 02 width: 32 bits clock: 33MHz configuration: latency=0 resources: ioport:400(size=32) *-scsi physical id: 1 bus info: usb@1:4 logical name: scsi2 capabilities: emulated scsi-host configuration: driver=usb-storage *-disk description: SCSI Disk physical id: 0.0.0 bus info: scsi@2:0.0.0 logical name: /dev/sdb size: 3864MiB (4051MB) capabilities: partitioned partitioned:dos configuration: signature=000b4c55 *-volume description: EXT4 volume vendor: Linux physical id: 1 bus info: scsi@2:0.0.0,1 logical name: /dev/sdb1 logical name: / version: 1.0 serial: 33926e39-4685-4f63-b83c-f2a67824b69a size: 3862MiB capacity: 3862MiB capabilities: primary bootable journaled extended_attributes large_files huge_files dir_nlink recover extents ext4 ext2 initialized configuration: created=2011-10-11 14:03:46 filesystem=ext4 lastmountpoint=/ modified=2012-03-19 11:47:29 mount.fstype=ext4 mount.options=rw,noatime,errors=remount-ro,barrier=1,data=ordered mounted=2012-04-15 11:31:11 state=mounted rfkill list all Doesnt show anything! dmesg | grep -i firmware [ 0.715481] pci 0000:00:1f.0: [Firmware Bug]: TigerPoint LPC.BM_STS cleared

    Read the article

  • Restoring GRUB2 on Software RAID 0 after Windows 7 wiped it using LiveCD

    - by unknownthreat
    I have installed Ubuntu 10.10 on my system. However, I need to install Windows 7 back, and I expect that it would alter GRUB and it did. Right now, my partition on my Software RAID 0 looks like this: nvidia_acajefec1 is Ubuntu 10.10 and nvidia_acajefec3 is Windows 7. I've been following some guides around and I am always stuck at GRUB not able to detect the usual RAID content. I've tried running: sudo grub > root (hd0,0) GRUB complains it couldn't find my hard disk. So I tried: find (hd0,0) And it complains that it couldn't find anything. So I tried: find /boot/grub/stage1 It said "file not found". Here's the text from the console: ubuntu@ubuntu:~$ grub Probing devices to guess BIOS drives. This may take a long time. [ Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists the possible completions of a device/filename. ] grub> root (hd0,0) root (hd0,0) Error 21: Selected disk does not exist grub> find /boot/grub/stage1 find /boot/grub/stage1 Error 15: File not found Fortunately, I got one person suggesting that what I've been trying to do is for GRUB Legacy, not GRUB2. So I went to the suggested website, ** (http://grub.enbug.org/Grub2LiveCdInstallGuide) **try to look around, and try: ubuntu@ubuntu:~$ sudo fdisk -l Unable to seek on /dev/sda This is just the step 2 of the instruction in the http://grub.enbug.org/Grub2LiveCdInstallGuide and I cannot proceed because it cannot seek /dev/sda. However, ubuntu@ubuntu:~$ sudo dmraid -r /dev/sdb: nvidia, "nvidia_acajefec", stripe, ok, 488397166 sectors, data@ 0 /dev/sda: nvidia, "nvidia_acajefec", stripe, ok, 488397166 sectors, data@ 0 So what now? Do you have an idea for how to make fdisk see my RAID array on live cd (Ubuntu 10.10)? Honestly, I am lost, very lost in trying to restore GRUB2 on this software RAID 0 system right now.

    Read the article

  • Raid Shows Up as Multiple Drives - Can't Mount

    - by manyxcxi
    I have a single hard drive that the OS is installed on and I have Sil raid card installed with two matching 500GB hdds set up in Raid 0 and formatted- they're completely empty. For whatever reason they are showing up as /dev/sdb and /dev/sdc and not as a single hard drive. I used fdisk to format both raid drives as Linux raid auto (fd) but I cannot mount either device and dmraid doesn't seem to want to work, what step am I missing? When I installed 9.04 oh so long ago it seems like it recognized and automatically did everything that needed to be done, now I'm stuck. dmraid Output root@tripoli:~# dmraid -r /dev/sdc: sil, "sil_biaebhadcfcb", stripe, ok, 976771072 sectors, data@ 0 /dev/sdb: sil, "sil_biaebhadcfcb", stripe, ok, 976771072 sectors, data@ 0 root@tripoli:~# dmraid -ay RAID set "sil_biaebhadcfcb" already active fdisk Output root@tripoli:~# fdisk -l Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000b9b01 Device Boot Start End Blocks Id System /dev/sda1 * 1 32 248832 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 32 60802 488134657 5 Extended /dev/sda5 32 60802 488134656 8e Linux LVM Disk /dev/sdb: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x6ead5c9a Device Boot Start End Blocks Id System /dev/sdb1 1 60801 488384001 fd Linux raid autodetect Disk /dev/sdc: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xe6e2af28 Device Boot Start End Blocks Id System /dev/sdc1 1 60801 488384001 fd Linux raid autodetect

    Read the article

  • Restoring GRUB2 on Software RAID 0 using LiveCD after Windows 7 wiped it

    - by unknownthreat
    I have installed Ubuntu 10.10 on my system. However, I need to install Windows 7 back, and I expect that it would alter GRUB and it did. Right now, my partition on my Software RAID 0 looks like this: nvidia_acajefec1 is Ubuntu 10.10 and nvidia_acajefec3 is Windows 7. I've been following some guides around and I am always stuck at GRUB not able to detect the usual RAID content. I've tried running: sudo grub > root (hd0,0) GRUB complains it couldn't find my hard disk. So I tried: find (hd0,0) And it complains that it couldn't find anything. So I tried: find /boot/grub/stage1 It said "file not found". Here's the text from the console: ubuntu@ubuntu:~$ grub Probing devices to guess BIOS drives. This may take a long time. [ Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists the possible completions of a device/filename. ] grub> root (hd0,0) root (hd0,0) Error 21: Selected disk does not exist grub> find /boot/grub/stage1 find /boot/grub/stage1 Error 15: File not found Fortunately, I got one person suggesting that what I've been trying to do is for GRUB Legacy, not GRUB2. So I went to the suggested website, ** (http://grub.enbug.org/Grub2LiveCdInstallGuide) **try to look around, and try: ubuntu@ubuntu:~$ sudo fdisk -l Unable to seek on /dev/sda This is just the step 2 of the instruction in the http://grub.enbug.org/Grub2LiveCdInstallGuide and I cannot proceed because it cannot seek /dev/sda. However, ubuntu@ubuntu:~$ sudo dmraid -r /dev/sdb: nvidia, "nvidia_acajefec", stripe, ok, 488397166 sectors, data@ 0 /dev/sda: nvidia, "nvidia_acajefec", stripe, ok, 488397166 sectors, data@ 0 So what now? Do you have an idea for how to make fdisk see my RAID array on live cd (Ubuntu 10.10)? Honestly, I am lost, very lost in trying to restore GRUB2 on this software RAID 0 system right now.

    Read the article

  • Switching mdadm to an external bitmap

    - by Oli
    I've just read this in another post about improving RAID5/6 write speeds: After increasing stripe cache & switching to external bitmap, my speeds are 160 Mb/s writes, 260 Mb/s reads. :-D I've already found out how to increase the stripe cache and this worked pretty well but I'd like to know more about an external bitmap. I have an incredibly fast (540MB/s) RAID0 SSD that would do well if a bitmap does what I think it does but I'm still very unsure. I've only known about them as long as I've known this post. A few questions: What is a bitmap (in terms of mdadm)? What are the advantages of an internal bitmap (over external)? What are the advantages of an external bitmap (over internal)? How do I switch between the two? I should add that while this is a I'm-bored-let's-break-something thread, I do value the data stored on the RAID array. If doing this is going to put data at significant risk, please let me know.

    Read the article

  • jquery: call functions immediately after plugin

    - by Dave
    I'm sure that there's an easy answer to this, but I can't find it. I have a table 'myTable' which I stripe using the following $("#myTable tr:even").css({ "background-color": "#FEE996" }); $("#myTable tr:odd").css({ "background-color": "#FFEFAF" }); This works fine. I am also using a table filter plugin as follows $('#myTable').tableFilter(); This plugin places a blank field at the top of each column into which the filter criteria can be typed. When the table is filtered it removes unmatched rows, which in turn messes up the striping. I would like to be able to re-invoke the lines to re-stripe the table. Something like $('#myTable').tableFilter().find("tr:even").css({ "background-color": "#FEE996" }).find("tr:even").css({ "background-color": "#FFEFAF" }); Is this possible please?

    Read the article

  • List/Grid Toggle for Photo Gallery with Shadowbox

    - by InfamouslyBubbly
    so I'm new to this site, and new to jquery, and javascript as a whole really, but I have very good comprehension of HTML and CSS. For a class in school, I'm making a photo gallery webpage using the Shadowbox plugin. I have that part all down, but one of the requirements is to add some sort of user option that the user can change that will get saved in a cookie. (I haven't gotten to the cookie part yet) For my option, I decided to add a toggle that will switch the view of the page from a grid view (default) with images, to a list view of just the captions of the images. I figured out how to do that, but decided it could probably done in a much simpler fashion with the use of loops. Here is the HTML I have: <body> <div id="preferences"> <h1>My Photo Gallery</h1> <ul id="options"> <li><a href="#" id="list"><img src="media/listview.png" alt="List view"/></a></li> <li><a href="#" id="grid"><img src="media/gridview.png" alt="List view"/></a></li> </ul> </div> <div id="gallery"> <a rel="shadowbox[Gallery]" class="l1 img" href="media/img1.jpg" title="Black and White Leopard Pattern"><img src="media/thumb1.jpg" alt="Black and White Leopard Pattern"/></a> <a rel="shadowbox[Gallery]" class="l2 img" href="media/img2.jpg" title="Snow Leopard Pattern"><img src="media/thumb2.jpg" alt="Snow Leopard Pattern"/></a> <a rel="shadowbox[Gallery]" class="l3 img" href="media/img3.jpg" title="Colorful Triangle Pattern"><img src="media/thumb3.jpg" alt="Colurful Triangle Pattern"/></a> <a rel="shadowbox[Gallery]" class="l4 img" href="media/img4.jpg" title="Tie Dye Zebra Stripe Pattern"><img src="media/thumb4.jpg" alt="Tie Dye Zebra Stripe Pattern"/></a> <a rel="shadowbox[Gallery]" class="l5 img" href="media/img5.jpg" title="Blue Knitted Pattern"><img src="media/thumb5.jpg" alt="Blue Knitted Pattern"/></a> <a rel="shadowbox[Gallery]" class="l6 img" href="media/img6.jpg" title="Black and White Damask Pattern"><img src="media/thumb6.jpg" alt="Black and White Damask Pattern"/></a> <a rel="shadowbox[Gallery]" class="l7 img" href="media/img7.jpg" title="Wooden Panel Pattern"><img src="media/thumb7.jpg" alt="Wooden Panel Pattern"/></a> <a rel="shadowbox[Gallery]" class="l8 img" href="media/img8.jpg" title="Brick Pattern"><img src="media/thumb8.jpg" alt="Brick Pattern"/></a> <a rel="shadowbox[Gallery]" class="l9 img" href="media/img9.jpg" title="Watercolor Pattern"><img src="media/thumb9.jpg" alt="Watercolor Pattern"/></a> <a rel="shadowbox[Gallery]" class="l10 img" href="media/img10.jpg" title="Orange Stripe Pattern"><img src="media/thumb10.jpg" alt="Orange Stripe Pattern"/></a> <a rel="shadowbox[Gallery]" class="l11 img" href="media/img11.jpg" title="Blue Scales Pattern"><img src="media/thumb11.jpg" alt="Blue Scales Pattern"/></a> <a rel="shadowbox[Gallery]" class="l12 img" href="media/img12.jpg" title="Woven Pattern"><img src="media/thumb12.jpg" alt="Woven Pattern"/></a> </div> </body> So here is the sample that works (for the list portion anyways), but seems excessive in terms of code since I'd have to repeat for each image: $(document).ready(function(){ $( "#list" ).click(function() { $( "a.l1" ).removeClass( "img" ); $( "a.l1" ).addClass( "lst" ); $( "a.l1" ).text( $( "a.l1" ).attr( "title" ); //repeat for l1 through l12 (that`s the letter L not a 1) }); $( "#grid" ).click(function() { $( "a.l1" ).removeClass( "lst" ); $( "a.l1" ).addClass( "grid" ); //actually have no idea at all how to get this back to the original img tag other than maybe .innerHTML??? //repeat for l1 through l12 (again, that`s the letter L not a 1) }); }): And here is kinda how I'd like it (Y'know, except in a way that works) $(document).ready(function(){ var i = 1; var selcur = $( "'a.l" + i + "'" ); var title = selcur.attr( "title" ); var image = '<img src="media/thumb' + i + '.jpg" alt="' + title + '"/>'; $( "#list" ).click(function() { while (1<=12) { selcur.addClass("lst"); selcur.removeClass("img"); selcur.text( title ); i++; } i = 1; }); $( "#grid" ).click(function() { while (1<=12) { selcur.removeClass("lst"); selcur.addClass("img"); selcur.text( image ); i++; } i = 1; }); }); Please tell me how I am going about this wrong, keep in mind again I'm new to this, I appreciate any and all responses! Is there a better way to do this? I really want to keep it simple.

    Read the article

  • Creating mdraid device on top of other existing mdraid devices

    - by Dmitriusan
    I'm considering creating something like "hierarchical raid" and wondering whether it is possible using pure mdraid. Moreover, I'm going to boot from this device. I'm using Ubuntu Server 12.04 LTS with Grub2 bootloader. Motivation behind doing that is: I have 4 x 1tb 7200rpm disks. Two are newer and faster (up to 200mb/sec) and other two are slower (up to 140mb/sec). I want to create RAID-0 device from them. When creating such RAID-0 directly from 4 hard disks, I get summary speed up to ~480mb/sec. That is roughly 4*120mb/sec, so RAID-0 works with speed of the slowest device. I have an idea to create a separate RAID-0 md0 device from 500gb partitions of slower hard disks. Theoretically, this md0 device will have speed 2*140=240~280mb/sec. After that, I'm going to add this md0 device to RAID-0 with faster disks, finishing with up to 3*200=600mb/sec. Stripe-width for this raid will be 2x times bigger than for underlying raid with slow disks. Questions are: is it possible or I'm missing something? will that work as expected? can I boot from such consolidated raid device? any better ideas? any pitfalls? I don't want to use fakeraid for consolidating slow disks for multiple reasons (portability, ability to customize parameters and so on). PS Speed is needed for home virtualization server and just for experience/fun. Reliability is provided via regular automatic backups to a separate device. PPS I considered also using different stripe-width for hard disks with different speed in single raid, but mdraid does not seem to support that.

    Read the article

  • Raid-5 Performance per spindle scaling

    - by Bill N.
    So I am stuck in a corner, I have a storage project that is limited to 24 spindles, and requires heavy random Write (the corresponding read side is purely sequential). Needs every bit of space on my Drives, ~13TB total in a n-1 raid-5, and has to go fast, over 2GB/s sort of fast. The obvious answer is to use a Stripe/Concat (Raid-0/1), or better yet a raid-10 in place of the raid-5, but that is disallowed for reasons beyond my control. So I am here asking for help in getting a sub optimal configuration to be as good as it can be. The array built on direct attached SAS-2 10K rpm drives, backed by a ARECA 18xx series controller with 4GB of cache. 64k array stripes and an 4K stripe aligned XFS File system, with 24 Allocation groups (to avoid some of the penalty for being raid 5). The heart of my question is this: In the same setup with 6 spindles/AG's I see a near disk limited performance on the write, ~100MB/s per spindle, at 12 spindles I see that drop to ~80MB/s and at 24 ~60MB/s. I would expect that with a distributed parity and matched AG's, the performance should scale with the # of spindles, or be worse at small spindle counts, but this array is doing the opposite. What am I missing ? Should Raid-5 performance scale with # of spindles ? Many thanks for your answers and any ideas, input, or guidance. --Bill Edit: Improving RAID performance The other relevant thread I was able to find, discusses some of the same issues in the answers, though it still leaves me with out an answer on the performance scaling.

    Read the article

  • Created nested model setting a property on nested model before save

    - by CWitty
    I have two models a Company and a User the Company has_many :users and the User belongs_to :company. I have a form such as: <%= form_for @company, data: {toggle: :validator}, novalidate: "novalidate", html: {role: :form} do |f| %> company fields Then in there I have <%= f.fields_for :users, @company.users.build do |user_form| %> A bunch of user fields It posts the data with the nested attributes of users_attributes: {"0" => {name: "Chad"}} But it doesn't create the user only the company object. Company Model class Company < ActiveRecord::Base has_many :users, dependent: :destroy has_many :contacts, dependent: :destroy accepts_nested_attributes_for :users accepts_nested_attributes_for :contacts attr_accessor :card_token, :users_attributes before_create :create_company_customer_token before_create :create_admin_user before_destroy :set_deleted_flag validates_presence_of :name, :phone_number private def create_admin_user self.users.first.admin = true end def set_deleted_flag self.deleted = true save users.each do |u| u.destroy end false end def create_company_customer_token begin customer = Stripe::Customer.create(description: "Company: #{self.name}", card: self.card_token, plan: self.plan) self.stripe_customer_id = customer['id'] rescue Stripe::StripeError => e self.errors.add(:stripe_customer_id, "Looks like we are having an issue at the moment, please try again shortly") @logger ||= Rails.logger @logger.error(e) end end end User Model class User < ActiveRecord::Base include Clearance::User has_many :messages belongs_to :company before_destroy :set_deleted_flag after_create :send_welcome_email validates_presence_of :first_name, :last_name validates_uniqueness_of :email, scope: :company_id, conditions: -> { where.not(deleted: true) } def name "#{first_name} #{last_name}" end private def set_deleted_flag self.deleted = true save end def send_welcome_email UserMailer.welcome_email(self).deliver end end

    Read the article

  • Is it possible to run my Windows Form application in Windows CE platform?

    - by Fakhrul
    I am new in Windows CE development and never done it yet. Need some advise from the expert in here. In our current project, we are developing a client-server application. The client side is using a windows form application that are base on Windows XP OS while the server is a web base application. This question are related to the client application (Windows Form). This application are using Sql Server Express Edition for data storage. The data is stored in XML object format. It also can transfer a data from client to server via web service. It also interact with hardware such as Magnetic Stripe Reader, Contactless Smart Card Reader, and a thermal printer. Most of the communication between hardware device and systems are base on Serial Port. It is use standard app.config for the configuration and is a multi threaded application. There is a new requirement to use a Handheld device which is use a Windows CE platform. This handheld included the required equipment such as Contactless Smart Card Reader, Printer and Magnetic Stripe Reader. Instead of developing a new client application, is it possible to me to convert my current application that are base on Windows XP to Windows CE? If yes, how can I do that? If no, is it any other brilliant suggestion to do this? Thanks in advance. Software Engineer

    Read the article

  • CSS Width Greater then Page Width without Horizontal Scroll (overflow:hidden not an option)

    - by Anders H
    I've got a basic layout going in 960.gs. One line of text is absolutely positioned, starting within an inner DIV and exiting only the right side of the page. Here's a screenshot: The issue is that as the text appears as a series of unbroken words, if the width of the text box doesn't extend beyond the end of the page, it breaks some distance from the edge. overflow: hidden; doesn't do the trick because I need to set the width wider than the page. float won't work because the text can't escape the width of the inner DIV. I can't set it outside the inner DIV and just position it there as the same problem will still exist. The code is basically as simple as: <wrapper (containing) DIV> <text stripe DIV> <p></p> </text stripe DIV> </ wrapper DIV> I know I've done something like this before and I can't for the life of me remember what I ended up doing. Thanks.

    Read the article

  • Striped table rows in ASP.NET MVC (without using jQuery or equivalent)

    - by Richard Ev
    When using an ASP.NET WebForms ListView control to display data in an HTML table I use the following technique in to "stripe" the table rows: <ItemTemplate> <tr class="<%# Container.DisplayIndex % 2 == 0 ? "" : "alternate" %>"> <!-- table cells in here --> </tr> </ItemTemplate> With the following CSS: tr.alternate { background-color: #EFF5FB; } I have just gone through the ASP.NET MVC Movie Database Application tutorial and learnt that in MVC-land table rows can be (must be?) constructed as follows: <% foreach (var item in Model) { %> <tr> <td> <%= Html.Encode(item.Title) %> </td> <!-- and so on for the rest of the table cells... --> </tr> <% } %> What can I add to this code to stripe the rows of my table? Note: I know that this can be done using jQuery, I want to know if it can be done another way. Edit If jQuery (or equivalent) is in your opinion the best or most appropriate post, I'd be interested in knowing why.

    Read the article

  • Quantifying the effects of partition mis-alignment

    - by Matt
    I'm experiencing some significant performance issues on an NFS server. I've been reading up a bit on partition alignment, and I think I have my partitions mis-aligned. I can't find anything that tells me how to actually quantify the effects of mis-aligned partitions. Some of the general information I found suggests the performance penalty can be quite high (upwards of 60%) and others say it's negligible. What I want to do is determine if partition alignment is a factor in this server's performance problems or not; and if so, to what degree? So I'll put my info out here, and hopefully the community can confirm if my partitions are indeed mis-aligned, and if so, help me put a number to what the performance cost is. Server is a Dell R510 with dual E5620 CPUs and 8 GB RAM. There are eight 15k 2.5” 600 GB drives (Seagate ST3600057SS) configured in hardware RAID-6 with a single hot spare. RAID controller is a Dell PERC H700 w/512MB cache (Linux sees this as a LSI MegaSAS 9260). OS is CentOS 5.6, home directory partition is ext3, with options “rw,data=journal,usrquota”. I have the HW RAID configured to present two virtual disks to the OS: /dev/sda for the OS (boot, root and swap partitions), and /dev/sdb for a big NFS share: [root@lnxutil1 ~]# parted -s /dev/sda unit s print Model: DELL PERC H700 (scsi) Disk /dev/sda: 134217599s Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 63s 465884s 465822s primary ext2 boot 2 465885s 134207009s 133741125s primary lvm [root@lnxutil1 ~]# parted -s /dev/sdb unit s print Model: DELL PERC H700 (scsi) Disk /dev/sdb: 5720768639s Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 34s 5720768606s 5720768573s lvm Edit 1 Using the cfq IO scheduler (default for CentOS 5.6): # cat /sys/block/sd{a,b}/queue/scheduler noop anticipatory deadline [cfq] noop anticipatory deadline [cfq] Chunk size is the same as strip size, right? If so, then 64kB: # /opt/MegaCli -LDInfo -Lall -aALL -NoLog Adapter #0 Number of Virtual Disks: 2 Virtual Disk: 0 (target id: 0) Name:os RAID Level: Primary-6, Secondary-0, RAID Level Qualifier-3 Size:65535MB State: Optimal Stripe Size: 64kB Number Of Drives:7 Span Depth:1 Default Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteThrough, ReadAdaptive, Direct, No Write Cache if Bad BBU Access Policy: Read/Write Disk Cache Policy: Disk's Default Number of Spans: 1 Span: 0 - Number of PDs: 7 ... physical disk info removed for brevity ... Virtual Disk: 1 (target id: 1) Name:share RAID Level: Primary-6, Secondary-0, RAID Level Qualifier-3 Size:2793344MB State: Optimal Stripe Size: 64kB Number Of Drives:7 Span Depth:1 Default Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteThrough, ReadAdaptive, Direct, No Write Cache if Bad BBU Access Policy: Read/Write Disk Cache Policy: Disk's Default Number of Spans: 1 Span: 0 - Number of PDs: 7 If it's not obvious, virtual disk 0 corresponds to /dev/sda, for the OS; virtual disk 1 is /dev/sdb (the exported home directory tree).

    Read the article

  • Linux RAID-0 performance doesn't scale up over 1 GB/s

    - by wazoox
    I have trouble getting the max throughput out of my setup. The hardware is as follow : dual Quad-Core AMD Opteron(tm) Processor 2376 16 GB DDR2 ECC RAM dual Adaptec 52245 RAID controllers 48 1 TB SATA drives set up as 2 RAID-6 arrays (256KB stripe) + spares. Software : Plain vanilla 2.6.32.25 kernel, compiled for AMD-64, optimized for NUMA; Debian Lenny userland. benchmarks run : disktest, bonnie++, dd, etc. All give the same results. No discrepancy here. io scheduler used : noop. Yeah, no trick here. Up until now I basically assumed that striping (RAID 0) several physical devices should augment performance roughly linearly. However this is not the case here : each RAID array achieves about 780 MB/s write, sustained, and 1 GB/s read, sustained. writing to both RAID arrays simultaneously with two different processes gives 750 + 750 MB/s, and reading from both gives 1 + 1 GB/s. however when I stripe both arrays together, using either mdadm or lvm, the performance is about 850 MB/s writing and 1.4 GB/s reading. at least 30% less than expected! running two parallel writer or reader processes against the striped arrays doesn't enhance the figures, in fact it degrades performance even further. So what's happening here? Basically I ruled out bus or memory contention, because when I run dd on both drives simultaneously, aggregate write speed actually reach 1.5 GB/s and reading speed tops 2 GB/s. So it's not the PCIe bus. I suppose it's not the RAM. It's not the filesystem, because I get exactly the same numbers benchmarking against the raw device or using XFS. And I also get exactly the same performance using either LVM striping and md striping. What's wrong? What's preventing a process from going up to the max possible throughput? Is Linux striping defective? What other tests could I run?

    Read the article

  • perf tuning for ESX vmfs3 on RAID

    - by maruti
    looking for recommendations on ESX4 OS - VMFS version3: RAID-5 : matching the stripe size with VMFS block size? (64K, 128K etc) RAID controller options: "adaptive read ahead, write-back" on PERC 6i 90% VMs on server are Windows (2008, 2003, Vista etc, SQL 2005 etc) i have read that smaller stipes are good for writes and larger for reads. Since this is virtual env, not sure whats good.

    Read the article

  • perf tuning for vmfs3 on RAID

    - by maruti
    recommendations for ESX4 OS - VMFS version3: matching: RAID-5 stripe size with VMFS block size? (64K, 128K etc) enabled "adaptive read ahead, write-back" on PERC 6i 90% VMs on server are Windows (2008, 2003, Vista etc, SQL 2005 etc) i have read that smaller stipes are good for writes and larger for reads. Since this is virtual env, not sure whats good.

    Read the article

  • Raid0 setup - What should 'my computer' say?

    - by superexsl
    Hey, I'm not a hardware person, so maybe someone here could help me. I ordered a PC from Dell that has "Serial ATA Raid 0 "Stripe"(7200RPM)Dual HDD" (2x500gb). However, I've just noticed that there's only one HD of 1TB (which is the default option when ordering). Should I be seeing two HDDs in "My Computer" or does the Raid0 setup simply improve performance rather than have (and display) two individual HDDs? How can I check if my computer does have a 'raid0' setup? Thanks

    Read the article

< Previous Page | 1 2 3 4 5 6  | Next Page >