Re: [SOLVED] Re: messed up changing chunk size

[Konstantin Svist <fry.kun@gmail.com>]

On 07/20/2010 09:30 AM, Konstantin Svist wrote:
> For some reason, mdadm refused to resize back to max:
>
> # mdadm --grow -z max --backup-file=/root/grow_md0_size_back.bak /dev/md0
> mdadm: component size of /dev/md0 has been set to 293033536K
> # cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4]
> md0 : active raid5 sdd1[3] sda4[0] sdc1[2] sdb1[1]
>       293033472 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
>
>
> After stopping and re-assembling the array, though, it comes up with 
> full size but with only 3 of 4 drives:
>
> # mdadm --assemble --scan
> mdadm: /dev/md0 has been started with 3 drives (out of 4).
> # cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4]
> md0 : active raid5 sda4[0] sdc1[2] sdb1[1]
>       879100608 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
>
> The array is degraded but data is all there, so I'm backing it up 
> right now. No idea why it doesn't like the 4th drive.
>

3 out of 4 was due to bad /etc/mdadm.conf -- I forgot the / in front of 
/dev/sdd1
It's now rebuilding and everything is fine so far