On Sun Sep 26, 2010 at 06:18:09AM -0400, Mike Hartman wrote:

quoted

You need to start looking in dmesg / other logs to see what has happened and
why things have failed. Without that information it's impossible to tell
what's going on.

I've uploaded the dmesg output starting with the reshape to
www.hartmanipulation.com/raid/dmesg_6.txt. It looks like /dev/sdd is
having some kind of intermittent read issues (which wasn't happening
before the reshape started) but I still don't understand why it
wouldn't be marked as failed in the md2 section of mdstat, since md0
is accessing it via md2.

I think this is because it's a RAID0 array.  It can't fail the device
without (irrecoverably) failing the array, so it's left to the normal
block device error reporting/handling process.

At any rate, that doesn't help me with my most immediate issue: does a
drive failing during a reshape corrupt the array? Or am I safe to
resume the reshape? Is there any way to restore my safety net a bit
before resuming the reshape, or will I just have to hope nothing else
goes wrong between now and the time the new hot spare is finally
incorporated?

Failure of a device during the reshape certainly shouldn't corrupt the
array (I don't see how it would anyway, unless there's a screw-up in the
code).  I don't think there's any way to "restore your safety net"
though (short of imaging all the drives as backups), but it's probably
worth while doing a read test of all member devices before you continue.

Cheers,
    Robin
-- 
     ___        
    ( ' }     |       Robin Hill        [off-list ref] |
   / / )      | Little Jim says ....                            |
  // !!       |      "He fallen in de water !!"                 |