[CentOS] ssacli start rebuild?

Fri Nov 6 19:38:08 UTC 2020
hw <hw at gc-24.de>

On Fri, 2020-11-06 at 12:08 +0100, Thomas Bendler wrote:
> Am Fr., 6. Nov. 2020 um 00:52 Uhr schrieb hw <hw at gc-24.de>:
> > [...]
> >       logicaldrive 1 (14.55 TB, RAID 1+0, Ready for Rebuild)
> > [...]
> Have you checked the rebuild priority:
> ❯ ssacli ctrl slot=0 show config detail | grep "Rebuild Priority"
>                                                       ~
>    Rebuild Priority: Medium
> Slot needs to be adjusted to your configuration.

Yes, I've set it to high:

ssacli ctrl slot=3 show config detail | grep Prior
   Rebuild Priority: High
   Expand Priority: Medium

Some search results indicate that it's possible that other disks in the
array have read errors and might prevent rebuilding for RAID 5.  I don't
know if there are read errors, and if it's read errors, I think it would
mean that these errors would have to affect just the disk which is
mirroring the disk that failed, this being a RAID 1+0.  But if the RAID
is striped across all the disks, that could be any or all of them.

The array is still in production and still works, so it should just rebuild.
Now the plan is to use another 8TB disk once it arrives, make a new RAID 1
with the two new disks and copy the data over.  The remaining 4TB disks can
then be used to make a new array.

Learn from this that it can be a bad idea to use a RAID 0 for backups and that
least one generation of backups must be on redundant storage ...