Multiple Disk Failure Recovery

Multiple Disk Failure Recovery

[Lane Brooks]

I have a RAID 5 setup with one spare disk.  One of the disks failed, so 
I replaced it, and while it was recovering, it found some bad sectors on 
another drive (unreadable and uncorrectable SMART errors).  This 
generated a fail event and shut down the array.

When I restart the array with the force command, it starts the recovery 
process and dies when it gets to the bad sectors, so I am stuck in an 
infinite loop.

I am wondering if there is a way to cut my losses with these bad sectors 
and have it recover what it can so that I can get my raid array back to 
functioning.  Right now I cannot get a spare disk recovery to finish 
because these bad sectors.  Is there a way to force as much recovery as 
possible so that I can replace this newly faulty drive?

Thanks
Lane

Re: Multiple Disk Failure Recovery

[David Rees]

On 10/14/06, Lane Brooks <lbrooks@mit.edu> wrote:
> I am wondering if there is a way to cut my losses with these bad sectors
> and have it recover what it can so that I can get my raid array back to
> functioning.  Right now I cannot get a spare disk recovery to finish
> because these bad sectors.  Is there a way to force as much recovery as
> possible so that I can replace this newly faulty drive?

One technique is to use ddrescue to create an image of the failing
drive(s) (I would image all drives if possible) and use those images
to try to retrieve your data.

-Dave

Re: Multiple Disk Failure Recovery

[Roger Gammans]

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On Sat, Oct 14, 2006 at 11:35:31PM -0700, David Rees wrote:
> On 10/14/06, Lane Brooks <lbrooks@mit.edu> wrote:
> >functioning.  Right now I cannot get a spare disk recovery to finish
> >because these bad sectors.  Is there a way to force as much recovery as
> >possible so that I can replace this newly faulty drive?
> 
> One technique is to use ddrescue to create an image of the failing
> drive(s) (I would image all drives if possible) and use those images
> to try to retrieve your data.


I'm currently writing error supression md layer precisely for situations
like this to remove the need for the dd step. 

Obvisouly it doesn't recover the data in the bad sectors or masked by errors
but the aim is to reduce to need of doing multiple copies which
recoversy procdure tend to invovle.

TTFN
-- 
Roger.                          Home| http://www.sandman.uklinux.net/
Master of Peng Shui.      (Ancient oriental art of Penguin Arranging)
Work|Independent Sys Consultant | http://www.computer-surgery.co.uk/
So what are the eigenvalues and eigenvectors of 'The Matrix'? --anon

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