I'm running a Ubuntu server on a md RAID5. I started to have some issue with one disk, I received the following email from mdadm:
A DegradedArray event had been detected on md device /dev/md/0.
md0 : active raid5 sdb2[1](F) sdd2[2] sda2[0]
1952861184 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [U_U]
md1 : active raid0 sdb3[1] sdd3[2] sda3[0]
2927924736 blocks super 1.2 512k chunks
And the following from smartd :
Device: /dev/sdb [SAT], Self-Test Log error count increased from 0 to 2
Device info:
ST2000DM001-1CH164, S/N:Z1E3M3TE, WWN:5-000c50-050534ead, FW:CC24, 2.00 TB
md0 is my /, and md1 is just for some none important data.
So, sdb is definitely falling appart... The issue is, the system apparently crashed somehow, and is not booting anymore. Right after the bios the screen go black and that's it, nothing more... I was expecting it to still boot on 2 disk and be slow, but it's not the case. Any idea why ?
I would like to boot the server in degraded mode asap as I need the server to be running, but I don't know what to do. Can you suggest something ? From that I'll then be able to repaire the raid5 volume isn't it ?
Do you think the error is localised in the disk and I'll be able to repair and come back to a stable state, or the disk is dead and I need to buy a new one ?
Thanks for your help.