On 22 Jul 2022, Wols Lists spake thusly:
> On 22/07/2022 10:57, Nix wrote:
>> I thought all the work done to assemble raid arrays was done by mdadm?
>> Because that didn't change. Does the kernel md layer also get to say
>> "type wrong, go away"? EW. I'd hope nothing is looking at partition
>> types these days...
>
> As far as I know (which is probably the same as you :-) the kernel knows nothing about the v1 superblock format, so raid assembly
> *must* be done by mdadm.
>
> That's why, despite it being obsolete, people get upset when there's any mention of 0.9 going away, because the kernel DOES
> recognise it and can assemble those arrays.
Right. These are all v1.2, e.g. for one of them:
/dev/md125:
Version : 1.2
Creation Time : Mon Apr 10 10:42:31 2017
Raid Level : raid6
Array Size : 15391689216 (14678.66 GiB 15761.09 GB)
Used Dev Size : 5130563072 (4892.89 GiB 5253.70 GB)
Raid Devices : 5
Total Devices : 5
Persistence : Superblock is persistent
Update Time : Fri Jul 22 15:58:45 2022
State : active
Active Devices : 5
Working Devices : 5
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : loom:fast (local to host loom)
UUID : 4eb6bf4e:7458f1f1:d05bdfe4:6d38ca23
Events : 51202
Number Major Minor RaidDevice State
0 8 3 0 active sync /dev/sda3
1 8 19 1 active sync /dev/sdb3
2 8 35 2 active sync /dev/sdc3
4 8 51 3 active sync /dev/sdd3
5 8 83 4 active sync /dev/sdf3
