Intermittent ext3 corruption on external firewire Micronet1.5Tb RAID on FC3

['Andreas Dilger']

On May 17, 2005  02:42 -0500, Joseph D. Wagner wrote:
> > What I would do (if you don't mind overwriting the disk, presumably
> > not if it is just new and doesn't contain important data) is to
> > write a small test program to write the byte offset at the start of
> > every 4kB block on the disk, then read them all back and verify it
> > is correct.
> 
> That's what badblocks is for when doing a destructive write test.

Looking at the badblocks man page, I don't think this is true (though
I could be wrong).  If badblocks is only writing out a repetetive
pattern, and only verifying in 64-block chunks this will not detect
device block address aliasing because (a) the pattern doesn't depend
on the offset so will verify correctl, and (b) 64 blocks is likely
aligned to the same offset as where the device would concievably wrap.

Having this feature as part of badblocks (e.g. add "-t offset" pattern)
is probably a great place to do this because it is widely available
and already has most of the framework for this.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.