Re: RAID 6, 6 device array - all devices lost superblock

Peter Sanders
2022-08-31T17:48:52Z

encountering a puzzling situation.

dmsetup is failing to return.

root@superior:/mnt/backup# dmsetup status
sdg: 0 5860533168 snapshot 16/8388608000 16
sdf: 0 5860533168 snapshot 16/8388608000 16
sde: 0 5860533168 snapshot 16/8388608000 16
sdd: 0 5860533168 snapshot 16/8388608000 16
sdc: 0 5860533168 snapshot 16/8388608000 16
sdb: 0 5860533168 snapshot 16/8388608000 16

dmsetup remove sdg runs for hours.
Canceled it, ran dmsetup ls --tree and find that sdg is not present in the list.

dmsetup status shows:
sdf: 0 5860533168 snapshot 16/8388608000 16
sde: 0 5860533168 snapshot 16/8388608000 16
sdd: 0 5860533168 snapshot 16/8388608000 16
sdc: 0 5860533168 snapshot 16/8388608000 16
sdb: 0 5860533168 snapshot 16/8388608000 16

dmsetup ls --tree
root@superior:/mnt/backup# dmsetup ls --tree
sdf (253:3)
├─ (7:3)
└─ (8:80)
sde (253:1)
├─ (7:1)
└─ (8:64)
sdd (253:2)
├─ (7:2)
└─ (8:48)
sdc (253:0)
├─ (7:0)
└─ (8:32)
sdb (253:5)
├─ (7:5)
└─ (8:16)

any suggestions?

On Tue, Aug 30, 2022 at 2:03 PM Wols Lists <antlists@youngman.org.uk> wrote:
>
> On 30/08/2022 14:27, Peter Sanders wrote:
> >
> > And the victory conditions would be a mountable file system that passes a fsck?
>
> Yes. Just make sure you delve through the file system a bit and satisfy
> yourself it looks good, too ...
>
> Cheers,
> Wol