dreadnought
n00b
Joined: 09 Jun 2004
Posts: 21
Location: Linz, Austria
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 Posted: Fri Mar 18, 2005 1:33 pm Post subject: [HOWTO] raidreconf & pvresize with LVM2 |
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I just spent 2 days to expand my 6x160G RAID5 array by 2x160 disks, so I thought I better share my knowledge (no pain, no gain):
First I wasn't really sure about raidreconf, but a quick look at the source code and some reports on successful resize operations eventually convinced me
| Code: | raidstop /dev/md0
raidreconf -o /etc/raidtab.old -n /etc/raidtab -m /dev/md0 |
The resizing of the raid array had been successful, but I now had to somehow convince my lvm2 to resize the pv as I used the whole /dev/md0 as a pv and not just some partitions. The command pvresize actually exists, however it just drops out with a
| Code: | | Command not implemented yet. |
As backing up the whole data and starting again was not an option here is how i managed to resize the pv myself
| Code: | pvcreate -ff -u[the uuid of the raid] /dev/md0
vgcreate testing /dev/md0
vgcfgbackup --file raidnewsize testing
vgremove testing
rm /etc/lvm/archive/testing* |
The new volume group I temporarily created uses the correct size of the pv, so the trick is to merge the backup file of the old volume group (in my case /etc/lvm/backup/raid_array) with the backup file of the temporary testing volume group. You just have to replace the following line in the backup file of the old vg
| Code: | | pe_count = 228940 # 894.296 Gigabytes |
Now restore the modified backup and proceed as if pvresize has ever existed
| Code: | vgcfgrestore --file raidnewsize raid_array
lvextend -l 228940 /dev/raid_array/backup
resize2fs /dev/raid_array/backup |
Enjoy. However if things go terribly wrong it's always comforting to have a backup....  |
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Kernel & Hardware
