Hi, all --
I recently migrated our disk farm to a new box with a new OS build
(openSuSE from KNOPPIX). Aside from the usual challenges of setting
up the world again, I have a 3-device RAID5 volume that won't start.
The other metadevice is fine, though; I think we can say that the md
system is running. Soooooo ... Where do I start?
diskfarm:~ # cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md0 : active raid5 sdc1[3] sdd1[4] sdb1[0]
11720265216 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/3] [U_UU]
md127 : inactive sdl2[0](S) sdj2[3](S) sdf2[1](S)
2196934199 blocks super 1.2
unused devices: <none>
[No, I don't know why md127 was first a moment ago!] I tried reassembling
the device, but mdadm doesn't like it.
diskfarm:~ # mdadm --stop /dev/md127
mdadm: stopped /dev/md127
diskfarm:~ # mdadm --assemble --scan
mdadm: /dev/md/750Graid5md assembled from 1 drive - not enough to start the array.
mdadm: Found some drive for an array that is already active: /dev/md/0
mdadm: giving up.
mdadm: No arrays found in config file or automatically
But ... what's with just 1 drive?
diskfarm:~ # for D in /dev/sd[fjl] ; do parted $D print ; done
Model: ATA WDC WD7500BPKX-7 (scsi)
Disk /dev/sdf: 750GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
2 1049kB 750GB 750GB ntfs Linux RAID raid
3 750GB 750GB 134MB ext3 Linux filesystem
Model: ATA WDC WD7500BPKX-7 (scsi)
Disk /dev/sdj: 750GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
2 1049kB 750GB 750GB ntfs Linux RAID raid
3 750GB 750GB 134MB xfs Linux filesystem
Model: ATA Hitachi HDE72101 (scsi)
Disk /dev/sdl: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 1049kB 4227MB 4226MB primary ntfs diag, type=27
2 4227MB 754GB 750GB primary reiserfs raid, type=fd
3 754GB 754GB 134MB primary reiserfs type=83
4 754GB 1000GB 246GB primary reiserfs type=83
Slice 2 on each is the RAID partition, slice 3 on each is a little
filesystem for bare-bones info, and slice 4 on sdl is a normal basic
filesystem for scratch content.
diskfarm:~ # mdadm --examine /dev/sd[fjl]2 | egrep '/dev|Name|Role|State|Checksum|Events|UUID'
/dev/sdf2:
Array UUID : 88575f01:592167fd:bd9f9ba1:a61fafc4
Name : diskfarm:750Graid5md (local to host diskfarm)
State : clean
Device UUID : e916fc67:b8b7fc59:51440134:fa431d02
Checksum : 43f9e7a4 - correct
Events : 720
Device Role : Active device 1
Array State : AAA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdj2:
Array UUID : 88575f01:592167fd:bd9f9ba1:a61fafc4
Name : diskfarm:750Graid5md (local to host diskfarm)
State : clean
Device UUID : 0b847f84:83e80a3d:a0dc11e7:60bffc9f
Checksum : 9522782b - correct
Events : 177792
Device Role : Active device 2
Array State : A.A ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdl2:
Array UUID : 88575f01:592167fd:bd9f9ba1:a61fafc4
Name : diskfarm:750Graid5md (local to host diskfarm)
State : clean
Device UUID : cc53440e:cb9180e4:be4c38d4:88a676eb
Checksum : fef95256 - correct
Events : 177794
Device Role : Active device 0
Array State : A.. ('A' == active, '.' == missing, 'R' == replacing)
Slice f2 looks great, but slices j2 & l2 seem to be missing -- even though
they are present. Worse, the Events counter on sdf2 is frighteningly
small. Where did it go?!? So maybe I consider sdf2 failed and reassemble
from the other two [only] and then put f2 back in?
Definitely time to stop, take a deep breath, and ask for help :-)
TIA & HAND
:-D
--
David T-G
See http://justpickone.org/davidtg/email/
See http://justpickone.org/davidtg/tofu.txt
