I noticed a couple weeks ago that I kept getting errors in the logs for one of the disks in the multimedia array. This was upsetting, but since I had paid a little more for these disks to get the 5 year warranty, I wasn't too concerned. Then I did a warranty check on the disk. It was the disk that WD sent me to replace the last disk that failed.
After futzing with the WD support website, they had changed it since the last time I had to RMA a disk, I finally got an advance RMA setup. The disk arrived last week, but I was unable, until today, to get around to replacing it.
So I powered down the server, pulled the bad disk ( installed 2011-04-20 according to the label I put on it ) and put the new one in it's place. Then I rebooted. The system complained about a degraded array, was I sure I wanted to continue, even though I hit 'y', it dropped to a minimal recovery shell. sigh
Reboot, let's try this again. Same thing.
Reboot again, hit 'e' to edit the boot paramemeters in GRUB, add 'bootdegraded=true' and voila, it boots.
Now to it was as simple as:
Copy the partition map from the existing drive...
# sfdisk -d /dev/sde | sfdisk/dev/sda
Add the new disk into the array:
# mdadm --manage /dev/md127 --add /dev/sda1
And check on the progress:
# cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md127 : active raid1 sda1 sde1 1953511936 blocks [2/1] [U_] [>....................] recovery = 3.8% (75987264/1953511936) finish=218.8min speed=142988K/sec unused devices: <none>
Not too shabby!
# df -kh /multimedia/ Filesystem Size Used Avail Use% Mounted on /dev/mapper/raid--lvm-movies 1.8T 841G 882G 49% /multimedia
Now I just need to get the old drive back into the shipping box and get it back to WD so they don't charge me $220 for the replacement disk.