hot swapping harddrives (linux raid pt. 1)

20 Jun 2012

one of the disks in my RAID1 died. it was one of the 2TB disks, so i ordered a new one off newegg. it arrived today so i spent most of the day waiting until the evening when i was done using the computer. when it came time to swap out the disk, i thought i would be daring (or an idiot).

first, i had to figure out which disk it was, this turned out to be pretty easy. looking at /proc/mdstat i knew it was /dev/sde1 that had failed. then i looked in dmesg and found it was the western digital. so that made it easy.

i opened up the case (while leaving everything still powered on and running), unplugged the WD disk, pulled it out, replaced it with the new disk.

surprisingly when i went back to my desktop, /dev/sde was the new disk and was completely functional. i opened up cfdisk added a new partition which i left as linux. since it was going to be put into a raid, i figured the type didn’t matter (i’m also unsure if i even need to add a partition for linux software raids).

all that was left was adding it to the raid:

sudo mdadm /dev/md1 -a /dev/sde1

and in about 4 minute’s time, i was already syncing.