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I have recently added a WD 2TB green drive to two systems and am finding |
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terrible performance with btrfs on an LVM using these drives. |
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I just saw on the mythtv list about the sector size problem these drives |
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have where they have poor performance unless you can map the partitions |
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onto certain sector boundaries. |
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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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How can I map an lvm with 4 or more disks, only one of which is a "WD |
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Green drive" and containing multiple reiserfs and btrfs file systems for |
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best performance. As these drives look useful in a data centre because |
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of their power savings, I presume someone must have solved this already! |
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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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Is there an application that can analyze a disk for settings and |
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automatically list the best/recommended settings? This should be |
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scriptable anyway so I may end up going this way if someone hasn't gone |
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there first. |
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Yesterday, a backup using dirvish that used to take 3-5 minutes to a |
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reiserfs partition on lvm on an older disk took nearly 19 minutes to the |
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same server, same lvm but on a btrfs partition on the new WD drive the |
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lvm was extended onto. Delete performance is even worse :( |
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BillK |
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