Re: ATA disks and RAID controllers for database servers

>Furthermore, if the disk drives are lying to the controller, it's
>anybody's guess whether or not data ever actually gets to the disk.
>
>When is it safe to let blocks expire out of the controller cache?
>
>If your computer can't know if the data has been written (because of
>drives that lie), I can't imagine how the controller would (since the
>drives are lying to the controller, too).
>

As I understand it, there is only 1 lie : the actual write to the disk.
The receipt into the drive *cache* is not lied about - hence the
discussion on mlist.limux.kernel about capacitors to allow enough power
for a cache flush in a power off situation.

regards

Mark