* Re: HELP 13 disk raid 5 not starting
2005-11-15 23:16 ` Neil Brown
@ 2005-11-15 23:21 ` Jim Buttafuoco
2005-11-15 23:27 ` Dan Stromberg
2005-11-15 23:27 ` Jim Buttafuoco
2 siblings, 0 replies; 6+ messages in thread
From: Jim Buttafuoco @ 2005-11-15 23:21 UTC (permalink / raw)
To: Neil Brown; +Cc: linux-raid
I believe there were data access errors on the console (scrolling to fast to read). I will try the force and see what
happends.
---------- Original Message -----------
From: Neil Brown <neilb@suse.de>
To: jim@contactbda.com
Cc: linux-raid@vger.kernel.org
Sent: Wed, 16 Nov 2005 10:16:22 +1100
Subject: Re: HELP 13 disk raid 5 not starting
> On Tuesday November 15, jim@contactbda.com wrote:
> > all,
> >
> > I have a 13 disk raid 5 set with 4 disks marks as "clean" and the
> > rest marked as dirty.
>
> And important question to answer is 'how did this happen'?
>
> > When I do the following command
> > to start the raid set (md0) I get an error. Any ideas on how to
> > recover?
>
> Add '--force' to the 'mdadm --assemble' command. This tells mdadm to
> try really hard to assemble the array, modifying info in the
> super blocks if necessary.
> Be aware that though doing this will normally give you a working
> array, there may be data corruption within the array (it depends
> somewhat on the answer to that first important question).
> I would recommend at least an 'fsck' if that is practical.
>
> The array will be assembled degraded. You will need to add in a spare
> if you are happy that the data is sufficiently intact.
>
> NeilBrown
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
------- End of Original Message -------
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: HELP 13 disk raid 5 not starting
2005-11-15 23:16 ` Neil Brown
2005-11-15 23:21 ` Jim Buttafuoco
@ 2005-11-15 23:27 ` Dan Stromberg
2005-11-15 23:30 ` Jim Buttafuoco
2005-11-15 23:27 ` Jim Buttafuoco
2 siblings, 1 reply; 6+ messages in thread
From: Dan Stromberg @ 2005-11-15 23:27 UTC (permalink / raw)
To: Neil Brown; +Cc: jim, linux-raid, strombrg
On Wed, 2005-11-16 at 10:16 +1100, Neil Brown wrote:
> On Tuesday November 15, jim@contactbda.com wrote:
> > all,
> >
> > I have a 13 disk raid 5 set with 4 disks marks as "clean" and the
> > rest marked as dirty.
>
> And important question to answer is 'how did this happen'?
>
> > When I do the following command
> > to start the raid set (md0) I get an error. Any ideas on how to
> > recover?
>
> Add '--force' to the 'mdadm --assemble' command. This tells mdadm to
> try really hard to assemble the array, modifying info in the
> super blocks if necessary.
> Be aware that though doing this will normally give you a working
> array, there may be data corruption within the array (it depends
> somewhat on the answer to that first important question).
> I would recommend at least an 'fsck' if that is practical.
>
> The array will be assembled degraded. You will need to add in a spare
> if you are happy that the data is sufficiently intact.
Before you do anything that might make things worse (--force is a good
thing to try, I'm sure, but sometimes the good thing to try causes
further problems, EG sometimes fsck goes kerflooey on ya), you might
want to see about getting an image backup of all the drives in the RAID
array to some other system, if you have the space. If your array wasn't
that full, you may be able to compress the image backups to good effect.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: HELP 13 disk raid 5 not starting
2005-11-15 23:27 ` Dan Stromberg
@ 2005-11-15 23:30 ` Jim Buttafuoco
0 siblings, 0 replies; 6+ messages in thread
From: Jim Buttafuoco @ 2005-11-15 23:30 UTC (permalink / raw)
To: Dan Stromberg, Neil Brown; +Cc: linux-raid
The disks contain a ~2TB Postgresql database so i was unable to copy to another system. The force worked as suggested
by Neil.
Thanks for the reply
Jim
---------- Original Message -----------
From: Dan Stromberg <strombrg@dcs.nac.uci.edu>
To: Neil Brown <neilb@suse.de>
Cc: jim@contactbda.com, linux-raid@vger.kernel.org, strombrg@dcs.nac.uci.edu
Sent: Tue, 15 Nov 2005 15:27:04 -0800
Subject: Re: HELP 13 disk raid 5 not starting
> On Wed, 2005-11-16 at 10:16 +1100, Neil Brown wrote:
> > On Tuesday November 15, jim@contactbda.com wrote:
> > > all,
> > >
> > > I have a 13 disk raid 5 set with 4 disks marks as "clean" and the
> > > rest marked as dirty.
> >
> > And important question to answer is 'how did this happen'?
> >
> > > When I do the following command
> > > to start the raid set (md0) I get an error. Any ideas on how to
> > > recover?
> >
> > Add '--force' to the 'mdadm --assemble' command. This tells mdadm to
> > try really hard to assemble the array, modifying info in the
> > super blocks if necessary.
> > Be aware that though doing this will normally give you a working
> > array, there may be data corruption within the array (it depends
> > somewhat on the answer to that first important question).
> > I would recommend at least an 'fsck' if that is practical.
> >
> > The array will be assembled degraded. You will need to add in a spare
> > if you are happy that the data is sufficiently intact.
>
> Before you do anything that might make things worse (--force is a good
> thing to try, I'm sure, but sometimes the good thing to try causes
> further problems, EG sometimes fsck goes kerflooey on ya), you might
> want to see about getting an image backup of all the drives in the RAID
> array to some other system, if you have the space. If your array wasn't
> that full, you may be able to compress the image backups to good effect.
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
------- End of Original Message -------
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: HELP 13 disk raid 5 not starting
2005-11-15 23:16 ` Neil Brown
2005-11-15 23:21 ` Jim Buttafuoco
2005-11-15 23:27 ` Dan Stromberg
@ 2005-11-15 23:27 ` Jim Buttafuoco
2 siblings, 0 replies; 6+ messages in thread
From: Jim Buttafuoco @ 2005-11-15 23:27 UTC (permalink / raw)
To: Neil Brown; +Cc: linux-raid
Neil,
Thanks for the reply, the --force worked great, md0 is syncing now, I will run testing against my database once the
sync completes in 400 minutes.
Jim
---------- Original Message -----------
From: Neil Brown <neilb@suse.de>
To: jim@contactbda.com
Cc: linux-raid@vger.kernel.org
Sent: Wed, 16 Nov 2005 10:16:22 +1100
Subject: Re: HELP 13 disk raid 5 not starting
> On Tuesday November 15, jim@contactbda.com wrote:
> > all,
> >
> > I have a 13 disk raid 5 set with 4 disks marks as "clean" and the
> > rest marked as dirty.
>
> And important question to answer is 'how did this happen'?
>
> > When I do the following command
> > to start the raid set (md0) I get an error. Any ideas on how to
> > recover?
>
> Add '--force' to the 'mdadm --assemble' command. This tells mdadm to
> try really hard to assemble the array, modifying info in the
> super blocks if necessary.
> Be aware that though doing this will normally give you a working
> array, there may be data corruption within the array (it depends
> somewhat on the answer to that first important question).
> I would recommend at least an 'fsck' if that is practical.
>
> The array will be assembled degraded. You will need to add in a spare
> if you are happy that the data is sufficiently intact.
>
> NeilBrown
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
------- End of Original Message -------
^ permalink raw reply [flat|nested] 6+ messages in thread