I'm testing a RAID10 array here with mdadm. I wanted to see how many failed devices it could tolerate, rebuild times, etc. At one point I had it doing a resync on 5 or 6 devices, then I rebooted it, Now it is showing inactive and I'm not sure what it is doing or how to get it back.
There's nothing important on there and I could just recreate it, but I'd prefer to figure out what went wrong and whether it can be recovered.
root@netcu1257-vs-02:~# cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : inactive sdz[19] sdy[18] sdx[17] sdw[16] sdv[15] sdu[14] sds[12] sdt[13] sdr[11] sdq[10](S) sdp[21] sdn[8] sdm[7] sdo[9] sdl[6] sdj[20](R) sdk[22](S) sdi[4](S) sdh[3] sdf[1] sde[0] sdg[2]
257812572160 blocks super 1.2
root@netcu1257-vs-02:~# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Fri Oct 29 13:59:41 2021
Raid Level : raid10
Used Dev Size : 18446744073709551615
Raid Devices : 20
Total Devices : 22
Persistence : Superblock is persistent
Update Time : Mon Nov 8 09:59:42 2021
State : active, FAILED, Not Started
Active Devices : 13
Working Devices : 22
Failed Devices : 0
Spare Devices : 9
Layout : near=2
Chunk Size : 512K
Consistency Policy : unknown
Name : netcu1257-vs-02:0 (local to host netcu1257-vs-02)
UUID : c3418360:4fb5857c:eb952018:163a60c6
Events : 85985
Number Major Minor RaidDevice State
- 0 0 0 removed
- 0 0 1 removed
- 0 0 2 removed
- 0 0 3 removed
- 0 0 4 removed
- 0 0 5 removed
- 0 0 6 removed
- 0 0 7 removed
- 0 0 8 removed
- 0 0 9 removed
- 0 0 10 removed
- 0 0 11 removed
- 0 0 12 removed
- 0 0 13 removed
- 0 0 14 removed
- 0 0 15 removed
- 0 0 16 removed
- 0 0 17 removed
- 0 0 18 removed
- 0 0 19 removed
- 65 112 17 sync set-B /dev/sdx
- 8 64 0 spare rebuilding /dev/sde
- 8 208 8 sync set-A /dev/sdn
- 65 80 15 sync set-B /dev/sdv
- 8 176 6 sync set-A /dev/sdl
- 65 48 13 sync set-B /dev/sdt
- 8 144 5 spare rebuilding /dev/sdj
- 65 16 11 sync set-B /dev/sdr
- 8 112 3 sync set-B /dev/sdh
- 8 240 7 spare rebuilding /dev/sdp
- 65 128 18 sync set-A /dev/sdy
- 8 80 1 sync set-B /dev/sdf
- 8 224 9 spare rebuilding /dev/sdo
- 65 96 16 sync set-A /dev/sdw
- 8 192 10 spare rebuilding /dev/sdm
- 65 64 14 sync set-A /dev/sdu
- 8 160 - spare /dev/sdk
- 65 32 12 sync set-A /dev/sds
- 8 128 - spare /dev/sdi
- 65 0 - spare /dev/sdq
- 65 144 19 sync set-B /dev/sdz
- 8 96 2 spare rebuilding /dev/sdg
As you can see, all of my devices (/dev/sd[e-z]) show up as part of md0, however it's also showing 20 missing devices. The original format of the array was 20 devices with 2 spares. And while it says it's rebuilding, there is no disk activity, and /proc/mdstat indicates the same.
Is this recoverable? And given that the array was rebuilding before the host was rebooted, what could I have done to ensure the rebuild would have continued and the array remain active after a reboot?
edit:
I found my mdadm.conf file had been incorrectly placed in /etc/. I moved it to /etc/mdadm/ and rebooted, now my array is showing as a RAID0, still inactive:
root@netcu1257-vs-02:~# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Raid Level : raid0
Total Devices : 22
Persistence : Superblock is persistent
State : inactive
Working Devices : 22
Name : netcu1257-vs-02:0 (local to host netcu1257-vs-02)
UUID : c3418360:4fb5857c:eb952018:163a60c6
Events : 85985
Number Major Minor RaidDevice
- 65 112 - /dev/sdx
- 8 64 - /dev/sde
- 8 208 - /dev/sdn
- 65 80 - /dev/sdv
- 8 176 - /dev/sdl
- 65 48 - /dev/sdt
- 8 144 - /dev/sdj
- 65 16 - /dev/sdr
- 8 112 - /dev/sdh
- 8 240 - /dev/sdp
- 65 128 - /dev/sdy
- 8 80 - /dev/sdf
- 8 224 - /dev/sdo
- 65 96 - /dev/sdw
- 8 192 - /dev/sdm
- 65 64 - /dev/sdu
- 8 160 - /dev/sdk
- 65 32 - /dev/sds
- 8 128 - /dev/sdi
- 65 0 - /dev/sdq
- 65 144 - /dev/sdz
- 8 96 - /dev/sdg
