Is there anything that can be done?
-----Original Message-----
From: Colt Boyd <coltboyd@xxxxxxxxx>
Sent: Saturday, June 8, 2019 10:48 AM
To: linux-raid@xxxxxxxxxxxxxxx
Subject: RAID-6 aborted reshape
I was resizing a raid6 array with a internal write intent bitmap from
5 3TB drives (in RAID6) to 6 drives. It was aborted very early in reshape via reboot and then reassembled with:
'mdadm -A /dev/md0 --force --verbose --update=revert-reshape --invalid-backup /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 /dev/sdg1'
When I reassembled it this way I incorrectly thought the backup file was zero bytes. It wasn't. I still have the intact backup file.
I’ve also since tried to reassemble it with the following create but the XFS fs is not accessible:
'mdadm --create /dev/md0 --data-offset=1024 --level=6 --raid-devices=5 --chunk=1024K --name=OMV:0 /dev/sdb1 /dev/sde1 /dev/sdc1 /dev/sdd1
/dev/sdf1 --assume-clean --readonly'
I can see the XFS FS on the drives, example:
root@OMV1:~# dd if=/dev/sde1 bs=512k count=5 | hexdump -C <snip>
00200000 58 46 53 42 00 00 10 00 00 00 00 00 82 f2 c3 00 |XFSB............|
00200010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00200020 4e 2b 04 64 e8 1b 49 d9 a5 20 b5 74 79 94 52 f8 |N+.d..I.. .ty.R.| <snip>
This is what it looked like immediately following the aborted reshape and before attempting to recreate it. This is from the drive that was being added at the time.
/dev/sdg1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : f8fdf8d4:d173da32:eaa97186:eaf88ded
Name : OMV:0
Creation Time : Mon Feb 24 18:19:36 2014
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 5858529280 (2793.56 GiB 2999.57 GB)
Array Size : 11717054464 (11174.25 GiB 11998.26 GB)
Used Dev Size : 5858527232 (2793.56 GiB 2999.57 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1960 sectors, after=2048 sectors
State : clean
Device UUID : 92e022c9:ee6fbc26:74da4bcc:5d0e0409
Internal Bitmap : 8 sectors from superblock
Update Time : Thu Jun 6 10:24:34 2019
Bad Block Log : 512 entries available at offset 72 sectors
Checksum : 8f0d9eb9 - correct
Events : 1010399
Layout : left-symmetric
Chunk Size : 1024K
Device Role : Active device 5
Array State : AAAAAA ('A' == active, '.' == missing, 'R' == replacing)
Where can I go from here to get this back?
