Growing RAID5 with mdadm not working in 2.6.17?
I have finally gone over to raid5 so that when a drive fails i wont loose anything. Now, I have bought a new 320gb drive which I want to add to the array. So I did mdadm --manage --add /dev/md2 /dev/sdb2. So now my mdstat looks like this,
md2 : active raid5 sdb2(S) hdb2 sda2 hdc1
586051072 blocks level 5, 64k chunk, algorithm 2 [3/3] [UUU]
so I now want to grow it, so I do mdadm --grow /dev/md2 --raid-disks=4 but for some reason I am getting the following,
mdadm: Need to backup 384K of critical section..
mdadm: Cannot set device size/shape for /dev/md2: Invalid argument
I tried adding --backup-file=/root/md2-backup as well but I still get the same error. Dmesg returns md: couldn't update array info. -22
What am I missing? I recompiled my raid5 module with reshape support, but that didnt change anything. I have also tried using --size=max as well but still nothing.