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On Monday 05 March 2007, Richard Freeman <rich@××××××××××××××.net> wrote |
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about '[gentoo-amd64] LVM2 Failures': |
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> Does anybody know what happens if an LVM2 physical volume fails? |
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> Obviously any data on that physical volume is lost, and I'd imagine any |
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> logical volumes that reside in part or whole on that physical volume |
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> would be a mess. |
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Right on both counts (assuming you haven't mirrored those extents to a |
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non-failed pv). |
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> What happens to logical volumes in the same volume group which do not |
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> reside on the lost physical volume? Are they easily recovered? |
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Yes. Simply activate your vg and lvs in partial mode (-P) and you will |
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have (at least) full read access to any lvs that do not have any extents |
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on the failed pv. |
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> How |
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> about logical volumes in a different volume group - are those affected |
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> at all? I didn't see any documentation on this topic on the lvm2 HOWTO. |
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No, vgs do not interact with one another. All vgs without any failed pvs |
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will behave completely normally. [Well, assuming the failed disk isn't |
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mucking up other things; like hanging the bus or whotnot.] |
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> Ideally I'd like to use lvm2 with the new drive. |
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LVM is nearly always a good choice, which is has been the default on |
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commercial unixes for a while. |
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> I'm trying to avoid RAID as I have a small collection of hard drives at |
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> this point and in order to set up RAID I'd need to toss just about all |
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> of them since they're of various sizes/speeds/etc. |
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Ooooor.... |
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Set up two (or 3 or 4) vgs that are roughly the same size (summed over all |
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their constituent pvs). Make a single lv on each and have all those lvs |
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be the same size. THEN, use software RAID 1 (or 5 or 6) on top of LVM. |
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(I'm not sure where mirroring support is on LVM2 -- it may be a viable |
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replacement for RAID 1 on top of LVM and it would simplify this setup |
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greatly.) |
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(Linux block devices are quite flexible in how they let you (ab)use them.) |
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-- |
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Boyd Stephen Smith Jr. ,= ,-_-. =. |
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bss03@××××××××××.net ((_/)o o(\_)) |
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ICQ: 514984 YM/AIM: DaTwinkDaddy `-'(. .)`-' |
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http://iguanasuicide.org/ \_/ |
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New GPG Key! Old key expires 2007-03-25. Upgrade NOW! |
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