vinum, 5.x performance, ... (was: Re: ANNOUNCE: GNOME 2.12.1 has been merged into the ports tree)

[Ion-Mihai Tetcu]

On Mon, 07 Nov 2005 14:56:45 +0100
Alexander Leidinger <Alexander at Leidinger.net> wrote:

> Ion-Mihai Tetcu <itetcu at people.tecnik93.com> wrote:
> 
> > On Mon, 07 Nov 2005 11:18:00 +0100
> > Alexander Leidinger <Alexander at Leidinger.net> wrote:
> >
> >> > - and performaces is a nightmare on atapi harddisks
> >>
> >> AFAIR 4.x enables the write cache (bad if there's a power failure
> >> in the soft-updates case, since without native command queueing the
> >> drivers may reorder writes witout the possibility to notify
> >> soft-updates about it),
> >
> > So on NCQ disks write_caching should be safe from consistency
> > point-of-view ?
> 
> AFAIK: Enabling the write cache doesn't mean you use NCQ. So just
> because your drive is able to do NCQ, you shouldn't enable the write
> cache. If your controller, your disk and the OS is able to use NCQ,
> and you enable the use of NCQ, then everything is fine... assuming
> the drive doesn't lie to you. AFAIR there are or there where some
> drives which lie(d), but I don't remember the details.

And finding out the what disk and controller use NCQ _and_ are
supported by our drivers can be done how ?


Thanks,

-- 
IOnut
Unregistered ;) FreeBSD "user"
  "Intellectual Property" is   nowhere near as valuable   as "Intellect"