Re: Odd data corruption problem with LVM/ReiserFS

[<pcg@goof.com ( Marc) (A.) (Lehmann )>]

On Mon, Feb 21, 2005 at 12:37:53PM +0100, Andreas Steinmetz <ast@domdv.de> wrote:
> >Anyway, what do you guys think could be the problem?  Could it be that
> >the LVM / Device Mapper snapshot feature is solely responsible for
> >this corruption?  (I'm sure there's a reason it's marked
> >Experimental).
> 
> I don't think so - I changed from reiserfs to ext3 without changing the 
> underlying dm/raid5 and this seems to work properly.

I use both reiserfs and ext3 on lvm/dm on raid.

Both filesystems have issues when restoring from backup (i.e. very heavy
write activity).

I did report this to the linux kernel, and got as reply that there are
indeed races *somewhere*, but as of yet there is no fix.

The symptoms are _not_ I/O errors (but until I see logs I wouldn't believe
you that there are real I/O errors), but usually too-high block numbers.

A reboot fixes this for both ext3 and reiserfs (i.e. the error is gone).

You might want to explore this problem and decide for yourself if it's caused
by I/O errors (in which case you have a disk problem) or "just" filesystem
corruption.

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