On Fri, 25 Feb 2022 15:22:00 +0800
Guoqing Jiang <guoqing.jiang@xxxxxxxxx> wrote:
> >> If one member disk was set Faulty which caused BROKEN was set, is
> >> it possible to re-add the same member disk again?
> >>
> > Is possible to re-add drive to failed raid5 array now? From my
> > understanding of raid5_add_disk it is not possible.
>
> I mean the below steps, it works as you can see.
>
> >> [root@vm ~]# echo faulty > /sys/block/md0/md/dev-loop1/state
> >> [root@vm ~]# cat /proc/mdstat
> >> Personalities : [raid6] [raid5] [raid4]
> >> md0 : active raid5 loop2[2] loop1[0](F)
> >> 1046528 blocks super 1.2 level 5, 512k chunk, algorithm 2
> >> [2/1] [_U] bitmap: 0/1 pages [0KB], 65536KB chunk
> >>
> >> unused devices: <none>
> >> [root@vm ~]# echo re-add > /sys/block/md0/md/dev-loop1/state
> >> [root@vm ~]# cat /proc/mdstat
> >> Personalities : [raid6] [raid5] [raid4]
> >> md0 : active raid5 loop2[2] loop1[0]
> >> 1046528 blocks super 1.2 level 5, 512k chunk, algorithm 2
> >> [2/2] [UU] bitmap: 0/1 pages [0KB], 65536KB chunk
> >>
> >> unused devices: <none>
In this case array is not failed (it is degraded). For that reason I
think that my changes are not related.
# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4] [raid1] [raid10]
md127 : active raid5 nvme5n1[1] nvme4n1[0](F)
5242880 blocks super 1.2 level 5, 512k chunk, algorithm 2 [2/1]
[_U]
unused devices: <none>
# cat /sys/block/md127/md/array_state clean
# mdadm -D /dev/md127
/dev/md127:
Version : 1.2
Creation Time : Thu Mar 3 18:49:53 2022
Raid Level : raid5
Array Size : 5242880 (5.00 GiB 5.37 GB)
Used Dev Size : 5242880 (5.00 GiB 5.37 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Thu Mar 3 18:52:46 2022
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Name : gklab-localhost:vol (local to host
gklab-localhost)
UUID : 711594e8:73ef988c:87a85085:b30c838d
Events : 8
Number Major Minor RaidDevice State
- 0 0 0 removed
1 259 9 1 active sync /dev/nvme5n1
0 259 5 - faulty /dev/nvme4n1
Do I miss something?
Thanks,
Mariusz
