Degraded RAID6... How can i readd the drive?

Hi,

I have:

Zitat

root@omv:~# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md126 : inactive sde[4](S)
3906887512 blocks super 1.2

md127 : active raid6 sda[0] sdf[7] sdg[6] sdh[5] sdd[3] sdc[2] sdb[1]
23441323008 blocks super 1.2 level 6, 512k chunk, algorithm 2 [8/7] [UUUU_UUU]

How can i get the sde back into my RAID?

I tried:

Zitat

root@omv:~# mdadm --stop /dev/md126
mdadm: stopped /dev/md126
root@omv:~# mdadm /dev/md127 --re-add /dev/sde
mdadm: --re-add for /dev/sde to /dev/md127 is not possible

But you can see it wont work...

HELP PLEASE

THX!

Should i use

Zitat

mdadm --zero-superblock /dev/sde

to delete the superblock and do a recover via webgui? It is not possible to readd the drive without a full resync (> 10 hours)?

Edit:

I did

Zitat

mdadm /dev/md127 --add /dev/sde

and now he makes a recovery...

Zitat

md127 : active raid6 sde[8] sda[0] sdf[7] sdg[6] sdh[5] sdd[3] sdc[2] sdb[1]
23441323008 blocks super 1.2 level 6, 512k chunk, algorithm 2 [8/7] [UUUU_UUU]
[>....................] recovery = 0.0% (2536308/3906887168) finish=564.4min speed=115286K/sec

as you can see that #4 is gone, i hope that will not be a problem at all?

Zitat von ryecoaaron

With one drive missing (#4), you are running the equivalent of raid 5.

damn... so how could i fix this?

thx

Zitat von ryecoaaron

You could try adding /dev/sdh like you did /dev/sde but I would wait until it is done syncing.

Hmm?

I don't get it... why sdh?

sde was the drive which was inactive.

Zitat von ryecoaaron

sde was the first one. You added it back. sdh is the one missing now.

md127 : active raid6 sde[8] sda[0] sdf[7] sdg[6] sdh[5] sdd[3] sdc[2] sdb[1]

sdh is on #5

hmmm

Zitat von ryecoaaron

What is the output of: cat /proc/mdstat

Zitat

root@omv:~# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md127 : active raid6 sda[0] sdf[7] sdg[6] sdh[5] sde[8] sdd[3] sdc[2] sdb[1]
23441323008 blocks super 1.2 level 6, 512k chunk, algorithm 2 [8/7] [UUUU_UUU]
[========>............] recovery = 41.7% (1632967260/3906887168) finish=363.1min speed=104365K/sec

unused devices: <none>

Zitat von ryecoaaron

How about: mdadm --detail /dev/md127

Zitat

root@omv:~# mdadm --detail /dev/md127
/dev/md127:
Version : 1.2
Creation Time : Tue Jul 29 17:22:29 2014
Raid Level : raid6
Array Size : 23441323008 (22355.39 GiB 24003.91 GB)
Used Dev Size : 3906887168 (3725.90 GiB 4000.65 GB)
Raid Devices : 8
Total Devices : 8
Persistence : Superblock is persistent

Update Time : Fri Aug 15 00:56:43 2014
State : clean, degraded, recovering
Active Devices : 7
Working Devices : 8
Failed Devices : 0
Spare Devices : 1

Layout : left-symmetric
Chunk Size : 512K

Rebuild Status : 42% complete

Name : omv:mycloud (local to host omv)
UUID : 5fc12491:1b6c288b:ce7fda7b:98997a3e
Events : 10865

Number Major Minor RaidDevice State
0 8 0 0 active sync /dev/sda
1 8 16 1 active sync /dev/sdb
2 8 32 2 active sync /dev/sdc
3 8 48 3 active sync /dev/sdd
8 8 64 4 spare rebuilding /dev/sde
5 8 112 5 active sync /dev/sdh
6 8 96 6 active sync /dev/sdg
7 8 80 7 active sync /dev/sdf

Alles anzeigen

Zitat von ryecoaaron

I guess it is still sde since it is marked as a spare (but rebuilding). That is good for you

so after the rebuild everything should be like it was before?

A RAID6 with 8 drives...

Zitat von ryecoaaron

I think so but it may be marked as a spare. If so, you may need to stop the array and re-assembed:

Code

mdadm --stop /dev/md127
mdadm --assemble --run --force /dev/md127 /dev/sd[abcdefgh]

great, thanks for your help!

The process is finished:

Zitat

root@omv:~# mdadm --detail /dev/md127
/dev/md127:
Version : 1.2
Creation Time : Tue Jul 29 17:22:29 2014
Raid Level : raid6
Array Size : 23441323008 (22355.39 GiB 24003.91 GB)
Used Dev Size : 3906887168 (3725.90 GiB 4000.65 GB)
Raid Devices : 8
Total Devices : 8
Persistence : Superblock is persistent

Update Time : Fri Aug 15 08:33:13 2014
State : clean
Active Devices : 8
Working Devices : 8
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : omv:mycloud (local to host omv)
UUID : 5fc12491:1b6c288b:ce7fda7b:98997a3e
Events : 10884

Number Major Minor RaidDevice State
0 8 0 0 active sync /dev/sda
1 8 16 1 active sync /dev/sdb
2 8 32 2 active sync /dev/sdc
3 8 48 3 active sync /dev/sdd
8 8 64 4 active sync /dev/sde
5 8 112 5 active sync /dev/sdh
6 8 96 6 active sync /dev/sdg
7 8 80 7 active sync /dev/sdf

Alles anzeigen

It looks like, that i have nothing to do?

Even though mdstat says

Zitat

root@omv:~# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md127 : active raid6 sda[0] sdf[7] sdg[6] sdh[5] sde[8] sdd[3] sdc[2] sdb[1]
23441323008 blocks super 1.2 level 6, 512k chunk, algorithm 2 [8/8] [UUUUUUUU]

the #4 is missing but it looks like that these numbers don't really matter at all?