Re: data corruption: ext3/lvm2/md/mptsas/vitesse/seagate

["Grant Grundler" <grundler@google.com>]

On Tue, Mar 25, 2008 at 7:17 PM, Marc Bejarano <beej@alum.mit.edu> wrote:
> At 20:12 3/25/2008, Grant Grundler wrote:
>   >On Tue, Mar 25, 2008 at 4:43 PM, Marc Bejarano <beej@alum.mit.edu> wrote:
>
>  >>  having never played with blocktrace, i have no idea what it's
>   >>  capabilities are.  can it be used to record not just the IOs, but
>   >>  also their timings?  any other ideas?  i'm at a loss for how to turn
>   >>  my reproducible test case into something i can send to seagate for
>   >>  investigation.
>   >
>   >Yes and yes (I think). But by itself, it won't help since block
>   >trace tools don't generally do any data validation.
>
>  we've been successfully using md's mirror consistency-checking
>  capabilities to spot the corruption.

Oh? Have you been running disktest on the mirrors or the individual disks?
I was expecting the latter but wonder now.

>  if we can get an IO pattern
>  that reproduces the issue, we're golden.  if only we didn't other
>  things to do with our time that were actually productive for us
>  ;)  hopefully we'll be able to report back soon-ish with more.

*sigh* this can take a long time to track down. And you right that
getting the "magic" workload to reproduce is key.

>
>  if anybody else has helpful ideas, we're all ears.
>
>  thanks, grant!

welcome,
grant

>
>  marc
>
>