[exim] Re: Reducing Disk OI - Speed Issues

On Thu, Aug 25, 2005 at 02:22:16PM +0100, Tony Finch said:
> On Thu, 25 Aug 2005, Walt Reed wrote:
>
> > In addition to other suggestions that were put forth, making sure your
> > RAID controller has battery backed write cache does AMAZING things for
> > performance.
>
> And check the disk write caches are turned off :-)

???

How so? I found the write cache sped most things up a LOT... Found it
helped my database by a factor of 2. Added the cache on all my machines
and overall load levels have dropped (as reported by MRTG. Especially
the IOWait state.)