Re: Unexpected RAIDframe behavior

[Greg Oster <oster%cs.usask.ca@localhost>]

On Tue, 3 Sep 2013 16:59:28 +0000 (UTC)
John Klos <john%ziaspace.com@localhost> wrote:

> >> Parity Re-write is 79% complete.
> >
> > OK, so this is really more about how parity checking works than
> > anything else (i guess.)
> >
> > for RAID1, it reads both disks and compares them, and if one
> > fails it will write the "master" data.  (more generally, it
> > reads all disks and if anything fails parity check it writes
> > corrected parity back to it.)
> 
> Ah, so a reboot caused RAIDframe to switch from reconstruction to
> parity creation. 

Hmm.. it shouldn't be 'switching'.... if reconstruction finished, but
you didn't have parity logging turned on, then you'd see the behaviour
you describe.  If reconstruction didn't finish, then you should see one
of the components still marked as 'failed'.

> That explains what was going on. However, it makes
> me wonder if the state of the RAID is not properly being maintained
> through reboot. I didn't really need all that non-zero data.

If the state of the RAID is not being maintained, then that's a bug,
and needs to be fixed right away.  To my knowledge, however, it does
maintain things correctly.  Feel free to file a PR with the specifics
of any failures in this regard...

Later...

Greg Oster