[Moosefs-users] Fwd: Re: moosefs losing chunks

[Ricardo J. B. <ric...@da...>]

Resending to the list, which was my original intention...

----------  Mensaje reenviado  ----------

Subject: Re: [Moosefs-users] moosefs losing chunks
Date: Jue 22 Diciembre 2011
From: "Ricardo J. Barberis" <ric...@da...>
To: Elliot Finley <efi...@gm...>

El Jue 22 Diciembre 2011, Ud. escribió:
> On Thu, Dec 22, 2011 at 3:11 AM, Chris Picton <ch...@ec...> wrote:
> > In my case, I had subsequently done a mfscheckfile recursively on my
> > entire filesystem, and noted the files with 0 chunks
> >
> > I ran a mfsfilerepair on those (not checking my messages file too
> > closely, and expecting the blocks to be zeroed out). My vms booted
> > correctly, and after running a forced fsck and rpm -Va, no errors were
> > detected.
> >
> > I am assuming I had the same scenario as you, where the previous chunk
> > version was restored, instead of being zeroed out (or by a large
> > coincidence, all failed chunks had not yet been allocated in the VM
> > disks yet)
>
> I went through the EXACT same scenario.  All VM images had one missing
> block.  I did a mfsfilerepair on all of them.  They all made it
> through a fsck with flying colors.  They all started and ran.  Over a
> month later, when the OS (FreeBSD) actually tried to access that
> block, things went berserk.  Long story short, I ended up recovering
> that VM from backups.
>
> Elliot

That's my fear also: possible silent corruption *inside* the VM.

In my case the files were not VM images but simple files from one of our 
websites, easily restored from local copies if necessary.

I'm curious if you had any erased chunks or all of them were restored to a 
previous version?

Regards,
-- 
Ricardo J. Barberis
Senior SysAdmin / ITI
Dattatec.com :: Soluciones de Web Hosting
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