Re: [PERFORM] Arguments Pro/Contra Software Raid

On Tue, 2006-05-09 at 20:02, Bruce Momjian wrote:
> Scott Marlowe wrote:
> > Actually, in the case of the Escalades at least, the answer is yes.
> > Last year (maybe a bit more) someone was testing an IDE escalade
> > controller with drives that were known to lie, and it passed the power
> > plug pull test repeatedly.  Apparently, the escalades tell the drives to
> > turn off their cache.  While most all IDEs and a fair number of SATA
> > drives lie about cache fsyncing, they all seem to turn off the cache
> > when you ask.
> >
> > And, since a hardware RAID controller with bbu cache has its own cache,
> > it's not like it really needs the one on the drives anyway.
>
> You do if the controller thinks the data is already on the drives and
> removes it from its cache.

Bruce, re-read what I wrote.  The escalades tell the drives to TURN OFF
THEIR OWN CACHE.