[Beowulf] MD check/scrub

Leif Nixon nixon at nsc.liu.se
Wed Nov 14 06:15:01 EST 2007


Mark Hahn <hahn at mcmaster.ca> writes:

>> If they find an inconsistent stripe they don't try to identify the
>> corrupt block. Instead, they dumbly *recompute P and Q*, which of
>> course makes the stripe consistent, but *leaves the corrupt data in
>> place*.
>
> I'm skeptical that MD would be so willfully stupid.

Me too, but I'm looking at a trashed test file at this very moment.

> did you conclude this from reading the code, empirical testing, or
> from the author?

Empirical testing, using raid 6 over file backed loop devices. I
*hope* there is something wrong with our methodology. We'll need to do
a proper summary of our findings and raise the issue on the linux-raid
mailing list.

-- 
Leif Nixon                       -            Systems expert
------------------------------------------------------------
National Supercomputer Centre    -      Linkoping University
------------------------------------------------------------
_______________________________________________
Beowulf mailing list, Beowulf at beowulf.org
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf

!DSPAM:473ad9d0191227511819938!



More information about the Beowulf mailing list