Re: Raid 5 - not clean and then a failure.

[Jon Hardcastle <jd_hardcastle@yahoo.com>]

--- On Wed, 26/8/09, Goswin von Brederlow <goswin-v-b@web.de> wrote:

> From: Goswin von Brederlow <goswin-v-b@web.de>
> Subject: Re: Raid 5 - not clean and then a failure.
> To: Jon@eHardcastle.com
> Cc: linux-raid@vger.kernel.org
> Date: Wednesday, 26 August, 2009, 12:18 PM
> Jon Hardcastle <jd_hardcastle@yahoo.com>
> writes:
> 
> > Guys,
> >
> > I have been having some problems with my arrays that I
> think i have nailed down to a pci controller (well I say
> that - it is always the drives connected to *a* controller
> but I have tried 2!) anyway the latest saga is i was trying
> some new kernel options last night - which didn't work.
> >
> > But when i booted up again this morning it said one of
> the drives was in an inconsistent state (not sure of the
> *exact* error message). I then kicked off an add of the
> drive and it started syncing. It got about 5% in and then
> the second drive in on that controller complained and the
> array failed. 
> >
> > Is there any hope for my data? If i get a good
> controller in there will the resync continue? can I try and
> tell it to assume the drives are good (which they ought to
> be)?
> >
> > Please help!
> 
> The inconsistency is probably just a block here or there
> and I'm
> assuming none of your drives actualy failed. So 99.9999% of
> your data
> should be there. Just rebooting might actualy just get your
> raid back
> (to syncing). If not then you have to force reassembly from
> the drives
> with the newest serials. That will give you some data
> corruption,
> whatever was writing when the controler gave errors. Worst
> case you
> have to recreate the raid with --assume-clean.
> 
> I recommend adding a bitmap to the raid. That way a
> wrongfully failed
> drive can be resynced in a matter of minutes instead of
> hours or
> days. Makes it way less likely another error occurs during
> resync.
> 
> MfG
>         Goswin
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> 

I did look into bitmaps *abit* i could easily have the imagine for my 6 drive raid 5 stored on the raid1 I have in the same system.. The googling I did tho did not paint a pretty picture it talked about huge performance hits?

-----------------------
N: Jon Hardcastle
E: Jon@eHardcastle.com
'Do not worry about tomorrow, for tomorrow will bring worries of its own.'
-----------------------


      
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