On 28/05/13 09:04, Mark Rogers wrote: [SNIP]
smartctl reports that neither disk had SMART enabled, which is odd because I thought they had, so there's no information there. I have enabled it this morning but don't want to try doing self-tests at this stage unless someone more knowledgeable than me says I should.
If you have a working backup, then I don't know that non-destructive smart tests would be a problem. I suppose it also makes a difference what sort of errors appear in the log - does it sound like a catastrophic drive hardware failure, or something that fsck could fix?
NB, Read to the end before doing anything!
I had some problems with S/W RAID. I have ubuntu, and I used the program called Disk Utility (that's the menu entry for it - I don't know what the actual name is). I clicked on the array, and checked and repair the array. I then re-added the faulty disk to the array, then re-checked the whole array.
Once that check had finished, the whole thing seemed to work for a bit, but then errors started recurring, so I decided to swap out both drives.
There are at least 2 ways to do this: If your hardware can cope with 4 drives plugged in at the same time, you could do this: Format and partition the new drives so that they are at least the same size as the partitions on the current partitions. Also ensure that the partitions are marked as active and bootable if the original ones are marked like this.
Increase the size of the raid array from 2 devices to 4 with no spares. Add the new drives as members of the raid array. I think you use mdadm to do this, but I don't exactly recall how. - GOOGLE IT!
Once these drives are added, mdadm should synchronise all the data from the existing drives onto the new ones. You can then use mdadm to remove the initial drives from the raid array, and reduce the raid array size back down to 2.
DO NOT REBOOT!
If these disks are the boot device, I think you need to do something to update the initramfs, otherwise the system won't boot. I've had a discussion in ALUG about this before. I'll root it out in a minute.
An alternative, if you can't run 4 disks at the same time, is to swap out sdb and replace it with a new one. Format and partition it, as described above, then add it to the array, wait for it to resync. Update initramfs. Shutdown, then swap out sda. Add the 2nd replacement disk. Format and partition it. Add it to the array. Wait for recync to finish. Update initramfs. Reboot and you're done.
Any resyncs will take a long time!
A third alternative, if you have complete backup, is to just remove the old disks, install new disks, then restore your backup. I don't know exactly how to go about this though, esp if the disks include your boot partition.
HTH TBC Steve
initramfs see alug