I have a weird mdadm situation.
I had a drive in a raid1 array go bad. I shut the machine down, and replaced the disk, did ddrescue (which succeeded without error) from the old non-failed drive to the new drive.
Now when I attempt to assemble, I get:
% sudo mdadm --verbose --assemble /dev/md3 /dev/sdg1 /dev/sdf1
mdadm: looking for devices for /dev/md3
mdadm: /dev/sdg1 is identified as a member of /dev/md3, slot 0.
mdadm: /dev/sdf1 is identified as a member of /dev/md3, slot 0.
mdadm: no uptodate device for slot 1 of /dev/md3
mdadm: added /dev/sdg1 to /dev/md3 as 0
mdadm: /dev/md3 assembled from 0 drives and 1 rebuilding - not enough to start the array.
and my cat /proc/mdstat
is
md3 : inactive sdf1[0](S)
7813894144 blocks super 1.2
output of examine
% sudo mdadm --examine /dev/sd[fg]1 21-08-21 - 12:13:27
/dev/sdf1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x2
Array UUID : 1a5dd664:54cdc95a:f0de5ce2:c8ea58f9
Name : arcana:3 (local to host arcana)
Creation Time : Wed Jan 18 14:06:34 2017
Raid Level : raid1
Raid Devices : 2
Avail Dev Size : 15627788288 (7451.91 GiB 8001.43 GB)
Array Size : 7813893952 (7451.91 GiB 8001.43 GB)
Used Dev Size : 15627787904 (7451.91 GiB 8001.43 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
Recovery Offset : 0 sectors
Unused Space : before=261864 sectors, after=384 sectors
State : clean
Device UUID : 5501a6d9:dfef5dbf:aae0b1cb:4692e6ec
Update Time : Fri Aug 13 11:19:08 2021
Bad Block Log : 512 entries available at offset 264 sectors
Checksum : 2b596499 - correct
Events : 2777
Device Role : Active device 0
Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdg1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x2
Array UUID : 1a5dd664:54cdc95a:f0de5ce2:c8ea58f9
Name : arcana:3 (local to host arcana)
Creation Time : Wed Jan 18 14:06:34 2017
Raid Level : raid1
Raid Devices : 2
Avail Dev Size : 15627788288 (7451.91 GiB 8001.43 GB)
Array Size : 7813893952 (7451.91 GiB 8001.43 GB)
Used Dev Size : 15627787904 (7451.91 GiB 8001.43 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
Recovery Offset : 0 sectors
Unused Space : before=261864 sectors, after=384 sectors
State : clean
Device UUID : 5501a6d9:dfef5dbf:aae0b1cb:4692e6ec
Update Time : Fri Aug 13 11:19:08 2021
Bad Block Log : 512 entries available at offset 264 sectors
Checksum : 2b596499 - correct
Events : 2777
Device Role : Active device 0
Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
I want to get this fixed (hopefully without losing any data). It seems like for the slots, one should be 0
and one should be 1
. How do I get this going? My googling has failed me and I don't want to "just try things" because I am a bit shy about destroying the data.