Re: Corrupt XFS -Filesystems on new Hardware and Kernel

Jan Kara
2007-03-29T09:58:45Z

> Oliver Joa wrote:
> >>eason or another, xfs has detected a corrupted on-disk inode format
> >>which it cannot recognize, and shuts down.
> ----
> Oh, one other thing that may not apply in your case, but may.
> Does your SATA disk support write caching? Does it support
> something called a barrier function? (not real clear on all
> the ways this can go wrong, but I believe barriers are supposed
> to guarantee previous data has been fixed on disk (not in write
> cache). If the SATA controller issues a reset, it may very well
> purge the write cache. Theoretically, I can think of a _possibility_,
> that the reset disk would purge the write cache and the barrier
> indicator would tell xfs to resume writing. From a recent thread
> on the xfs list, it would appear this could be a "bad" thing (like
> crossing the streams ala "ghostbusters", but in a data-integrity
> context).
As far as I can remember, barrier does not mean that data is fixed on
disk. It is only a command that forces all the writes before the barrier
to be performed before all the writes after the barrier. So this is more
an ordering restriction than a data integrity thing...

Honza
--
Jan Kara <jack@suse.cz>
SuSE CR Labs