On Thu, Mar 29 2007, Jan Kara wrote: > > 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...
A barrier write guarentees both data before barrier is on disk, as well as the barrier itself when completion is signalled. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/