Re: My superblocks have gone missing, can't reassemble raid5

On 19/05/2021 15:48, Leslie Rhorer wrote:

     Then I would try recreating the RAID based upon the earlier Examine 
report:

mdadm -C -f -n 3 -l 5 -e 1.2 -c 512 -p ls /dev/md99 /dev/loop2 
/dev/loop0 /dev/loop1

     You may notice some of the command switches are defaults.  Remember 
what I said about a belt and suspenders?  Personally, in such a case I 
would not rely on defaults.

Because defaults change?

     Now try running a check on the assembled array:
fsck /dev/md99

     If that fails, shutdown the array with

mdadm -S /dev/md99

     and then try creating the array with a different drive order.  
There are only two other possible permutations of three disks.  If none 
of those work, you have some more serious problems.

And here you are oversimplifying the problem immensely. If those three 
drives aren't the originals, then the chances are HIGH that a simple 
re-assembly/creation is going to fail your simplistic scenario.

That said, I couldn't agree more about getting new drive(s) to take a 
backup before attempting recovery ...

Cheers,
Wol