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From: Robin Hill <robin@robinhill.me.uk>
To: linux-raid@vger.kernel.org
Subject: Re: Accidental grow before add
Date: Sun, 26 Sep 2010 22:22:32 +0100	[thread overview]
Message-ID: <20100926212232.GB5719@cthulhu.home.robinhill.me.uk> (raw)
In-Reply-To: <AANLkTi=iUUT_qZdg7gtxfroT+Y-c92SKQbhtUGhWwE=e@mail.gmail.com>

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On Sun Sep 26, 2010 at 03:34:17PM -0400, Mike Hartman wrote:

> >> 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 guess I was thinking that the reshape was restriping all the data
> under the assumption of 7 (or 8) drives, and one failing might change
> the restriping requirements in midstream and leave it in an
> unrecoverable in-between state. Very glad to hear that's not the case.
> 
I've not looked at the code, so I can't be certain.  I'm pretty sure
I've had this happen to me during a reshape though, without any issues.

> > 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.
> 
> Can you recommend a good way to perform such a read test? Would I just
> dd the entire contents of each disk to /dev/null or is there a more
> efficient way of doing it?
> 
That's what I'd do anyway.  You could also try running a full SMART
test - that should pick up anything.  I'd still go with dd though, as
I'm more confident of what that's actually doing.

Good luck,
    Robin
-- 
     ___        
    ( ' }     |       Robin Hill        <robin@robinhill.me.uk> |
   / / )      | Little Jim says ....                            |
  // !!       |      "He fallen in de water !!"                 |

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  reply	other threads:[~2010-09-26 21:22 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-26  7:27 Accidental grow before add Mike Hartman
2010-09-26  9:39 ` Mike Hartman
2010-09-26  9:54   ` Mike Hartman
2010-09-26  9:59     ` Mikael Abrahamsson
2010-09-26 10:18       ` Mike Hartman
2010-09-26 10:38         ` Robin Hill
2010-09-26 19:34           ` Mike Hartman
2010-09-26 21:22             ` Robin Hill [this message]
2010-09-27  8:11 ` Jon Hardcastle
2010-09-27  9:05   ` Mike Hartman
2010-09-28 15:14     ` Nagilum
2010-10-05  5:18       ` Neil Brown
2010-09-30 16:13     ` Mike Hartman
2010-10-05  6:24       ` Neil Brown

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