On Wed, 2002-06-05 at 16:56, Florin Andrei wrote:
> On Wed, 2002-06-05 at 13:04, Thor Lancelot Simon wrote:
> >
> > More importantly, you don't *want* to use readahead because it will waste
> > valuable cache space on the controller that could be used to cache small
> > writes.
>
> How safe is it to enable caching for writes on the controller (if you
> don't have a battery on it)?
> I mean, i configured my Mylex with "Write Through" for data-safety
> reasons, even though the other option ("Write Back") could offer
> improved performance.
>
How important is your data? If it is in the cache and you lose power,
then you lose it. If the raid controller does reordering on the I/O
then you can end up with a corrupted file system. You will not know
it is corrupted until you attempt to access the part of it that is
corrupt, or run xfs_check on it.
Steve
--
Steve Lord voice: +1-651-683-3511
Principal Engineer, Filesystem Software email: lord@xxxxxxx
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