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> My problem is that LVM2 is not supported in parted which is the |
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> recommended tool to deal with this. |
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> |
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> I suspect I only need to map the individual PE to a particular start |
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> sector on each drive, not btrfs, but then there is stripe/block sizes to |
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> consider as well ... WD also are recommending 1mb sector boundaries for |
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> best performance - I can see a reinstall coming up :) |
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> |
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|
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I have on my workstation: |
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2 WD 2TB Black Drives |
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5 WD 2TB RE4 Drives |
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|
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Some notes: |
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- The black drives have horrible reliability, poor sector remapping, and have |
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certain standard drive features to make them unusable in raid. I would not |
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buy them again. I'm not sure how similar the green drives are. |
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- Many of the recent WD drives have a tendency to power down/up frequently |
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which can reduce drive lifetime (research it and ensure it is set |
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appropriately for your needs). |
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- Due to reliability concerns, you'll may need to run smartd to give adequate |
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pre-failure warnings |
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|
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Anyhow, in my config I have: |
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|
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1 RE4 Drive as Server Boot Disk |
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4 RE4 Drives in SW RAID10 (extremely good performance and reliability) |
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2 Black Drives in LVM RAID0 for disk-to-disk backups (thats about all I trust |
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them with). |
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|
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When I setup the LVM RAID0, I used the following commands to get good |
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performance: |
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fdisk (remove all partitions, you don't need them for lvm) |
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pvcreate --dataalignmentoffset 7s /dev/sdd |
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pvcreate --dataalignmentoffset 7s /dev/sdf |
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vgcreate -s 64M -M 2 vgArchive /dev/sdd /dev/sdf |
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lvcreate -i 2 -l 100%FREE -I 256 -n lvArchive -r auto vgArchive |
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mkfs.ext4 -c -b 4096 -E stride=64,stripe_width=128 -j -i 1048576 -L |
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/archive /dev/vgArchive/lvArchive |
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|
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I may have the ext4 stride/stripe settings wrong above, I didn't have my |
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normal notes when I selected them - but the rest of the config I scrounged |
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from other blogs and seemed to make sense (the --dataalignmentoffset 7s) seems |
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to be the key. |
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|
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My RAID10 drives are configured slightly different w/ 1 partition that starts |
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on sector 2048 if I remember and extends to the end of the drive. |
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|
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The 4 Disk SW RAID10 array gives me 255MB/s reads, 135MB/s block writes, and |
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98MB/s rewrites (old test, may need to rerun for latest changes/etc). |
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|
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LVM 2 Disk RAID0 gives 303MB/s reads, 190MB/s block writes, and 102MB/s |
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rewrites (test ran last week). |
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|
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Regards, |
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Matt |
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-- |
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Matthew Marlowe / 858-400-7430 / DeployLinux Consulting, Inc |
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Professional Linux Hosting and Systems Administration Services |
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www.deploylinux.net * matt@×××××××××××.net |
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'MattM' @ irc.freenode.net |