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On Wednesday 30 March 2011 07:28:40 Florian Philipp wrote: |
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> Am 30.03.2011 05:02, schrieb Einux: |
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> > Hi, |
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> > |
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> > I bought a new 1T harddrive which is exactly the same as my previous |
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> > harddrive. So I'm planning to make a Raid-1 layout(for security |
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> > reasons). But here's the problem: I've already setup LVM2 on the |
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> > existing harddrive and I don't want to destroy the existing LVM volume |
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> > groups. I tried to google it, but I'm not sure which is the right |
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> > keyword. Could you guys help me out? |
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> > |
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> > Thanks in advance:) |
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> |
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> 1. Create a degenerated RAID1 with your new disk |
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> mdadm --create /dev/md0 --level=1 --raid-devices=2 missing /dev/sdb |
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> |
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> 2. Partition the raid device |
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> |
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> 3. Add one of the partitions to your LVM volume group. |
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> pvcreate /dev/sdb2 |
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> vgextend volume_group /dev/sdb2 |
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> |
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> 4. Move everything from the old physical volumes to the new pv. |
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> pvmove /dev/sda3 /dev/sdb2 |
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> |
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> 5. Remove the old and now empty physical volume |
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> vgreduce volume_group /dev/sda3 |
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> |
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> 6. Move everything else which is not on LVM to your new raid. Guess you |
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> need to go to single user mode to do this safely. |
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> |
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> 7. Grow your raid to also contain the old disk. |
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> mdadm /dev/md0 -a /dev/sda |
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> |
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> No, I have not tested this and you should double-check everything. No |
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> guarantees, etc. |
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> |
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> One warning, though: pvmove is known to create problems from time to |
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> time. Leaking memory, bogging systems with infinite system load and so |
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> on. If it gives you trouble, you can abort it with `pvmove --abort` and |
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> try it again later by calling `pvmove volume_group` (without physical |
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> device specified) to resume it. It SHOULD survive system crashes. |
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> Trying another kernel version sometimes helps when pvmove gives you trouble. |
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|
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To avoid that, with "large" moves, do the following: |
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# pvmove -i 600 /dev/sda3 |
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The "-i 600" means, only report every 10 minutes. It's the "reporting" that |
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causes the memory leak. |
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Also, when just wanting to "empty" one physical volume, it is not necessary to |
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specify the "target". |
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It's a good idea to mark the PVs on the existing drive "non-allocatable". Then |
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LVM won't try to move anything to that PV: |
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# pvchange -xn /dev/sda3 |
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The rest of the steps read correct. It's how I did a similar operation, but |
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still double-check all the parameters and when in doubt, read the manual |
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and/or ask on the list. |
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|
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-- |
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Joost Roeleveld |
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