Topic: Clarity on replacing and upgrading SATA RAID disks

[kenironside]

I am looking for clarity on the procedure for replacing a failing RAID disk with a larger disk. I have read the RAID wiki (http://wiki.contribs.org/Raid).

This is the current state:
[root@blackdesk ~]# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sda2[0]
      312464128 blocks [2/1] [U_]

md1 : active raid1 sda1[0] sdb1[1]
      104320 blocks [2/2] [UU]

unused devices: <none>

I take it to mean that sdb2 is faulty and so <drive> sdb needs to be replaced. I want to take the opportunity to increase the storage size so I have bought 2 x 1Tb drives. I have two good backups.

My questions are these: What exactly do I need to do?
- Do I need to fail /dev/sdb before shutting down the box?
- Do I need to prepare the new drives (fdisk?) before putting one in to replace the current /dev/sdb?
- The wiki implies that all I have to do is shut down, replace the failing drive and restart, then log in as admin, select 'Manage Disk Redundancy' and there will be instructions on that page. Is this correct?
- Assuming this is correct and I get one of the 1Tb drives sync'ed, I then repeat the process and the wiki provides a set of commands to increase the size of the array to the full size of the new disks. Do I understand that I simply apply these commends and that is all that is required?

I really appreciate any assistance; I just need to understand the step by step process.

Thank you, Ken

[Stefano]

- Do I need to fail /dev/sdb before shutting down the box?

no

- Do I need to prepare the new drives (fdisk?) before putting one in to replace the current /dev/sdb?

no.. you have to erase their mbr if they were used with windows

- The wiki implies that all I have to do is shut down, replace the failing drive and restart, then log in as admin, select 'Manage Disk Redundancy' and there will be instructions on that page. Is this correct?

yes

- Assuming this is correct and I get one of the 1Tb drives sync'ed, I then repeat the process and the wiki provides a set of commands to increase the size of the array to the full size of the new disks. Do I understand that I simply apply these commends and that is all that is required?

yes

welcome here.. please take the time to read carefully the fine documentation.. link is above

[kenironside]

Just a short note to thank you for the information you gave. I have now replaced the drives and, with one exception, the process was as you describe - thank you for the excellent documentation, I apologise for needing to ask some question to put my mind at rest.

The exception came after I had added the first one of the big drives (in place of sdb) and synchronised the RAID. I then added the second big drive (as sda) and the server had a boot disk failure. This was fixed by swapping the drives so what was sdb became sda and all was well.

Regards, Ken