[mythtv-users] Totally OT - but need help wit RAID5 array

[Robin Hill]

On Thu Nov 16, 2006 at 04:20:15PM -0500, James Pifer wrote:

> > Well, your basic problem is that the disk would look to be hosed.  I'd
> > recommend stopping the RAID array (mdadm -S /dev/md0) and using dd (or,
> > even better, dd_rescue/dd-rhelp
> > http://www.kalysto.org/utilities/dd_rhelp/index.en.html) to copy
> > /dev/hdb to /dev/hdd.  You can then assemble the array using /dev/hdc
> > and /dev/hdd and try fscking it again.  I've managed to recover a failed
> > drive using this method before (though that wasn't in a RAID array).
> > 
> 
> I'm trying dd_rhelp right now. Would be nice to recover some of the
> stuff if I can. 
> 
> Assuming dd_rhelp is able to do it's thing (it appears to be doing
> something!), how do I bring up the array? Should I switch hdb and hdd in
> the cabling or just try and force the array to load using hdc and hdd?
> 
Either should work.  Since you're copying the entire disk then this will
include the RAID metadata so it'll look to be the same drive as the old
one.  The RAID system isn't bothered about the drive names, it just uses
that metadata.  This does mean that you'll need to erase the metadata
from the failed drive before you can add it back into the array (that's
if it's not totally dead of course).

Incidentally, you may well have lower than ideal performance as it looks
like you're running the array with a master/slave disk setup - ideally
each drive should be on its own IDE channel.

Cheers,
        Robin
-- 
     ___        
    ( ' }     |       Robin Hill        <myth at robinhill.me.uk>  |
   / / )      | Little Jim says ....                            |
  // !!       |      "He fallen in de water !!"                 |
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
Url : http://mythtv.org/pipermail/mythtv-users/attachments/20061116/839d8151/attachment.pgp