[Lustre-discuss] WARNING: data corruption issue found in 1.8.x releases

[Johann Lombardi]

On Sep 15, 2009, at 8:44 AM, Robin Humble wrote:
> as we are about to throw users onto the new system, can I ask for a
> quick update pointing us to the current best guess at a workaround/fix
> for the 1.8.1 read cache problems please?
>
> to me it looks like
>  https://bugzilla.lustre.org/show_bug.cgi?id=20560
> is still evolving, but it looks like writethrough_cache=0 should now
> work (and not crash the OSS) with attachment:
>  https://bugzilla.lustre.org/attachment.cgi?id=25833
>
> so if I patched our OSS's with just this one liner, then would that be
> enough to run with until the situation has had some time to bed in?

Yes.

> or would we be better off with all 4 patches from 20560 applied (and
> both read cache's still off)?

In fact, you don't need to apply the 4 patches to fix the problem, but
only attachment 25896 (about to land for 1.8.1.1). Once this patch
is applied, it is safe to run with OSS read cache turned on (that's
to say enabling both writethrough_cache_enable and
read_cache_enable). Since you have to recompile lustre in both
cases (we are doing our best  to release 1.8.1.1 asap), i would
recommend to apply both attachments 25833 and 25896.

Best regards,
Johann