[2509] in linux-scsi channel archive
Re: Adaptec 2940 support
daemon@ATHENA.MIT.EDU (Jeff Noxon)
Mon Sep 22 13:29:34 1997
Date: Mon, 22 Sep 1997 11:13:50 -0500
From: Jeff Noxon <jeff@planetfall.com>
To: Zlatko.Calusic@CARNet.hr
Cc: Jeff Noxon <jeff@planetfall.com>, linux-scsi@vger.rutgers.edu
In-Reply-To: <874t7dv15a.fsf@atlas.infra.CARNet.hr>; from Zlatko Calusic on Mon, Sep 22, 1997 at 05:06:25PM +0200
On Mon, Sep 22, 1997 at 05:06:25PM +0200, Zlatko Calusic wrote:
> Jeff Noxon <jeff@planetfall.com> writes:
>
> > This controller should work, but it's not great from a driver performance or
> > stability standpoint.
> >
>
> Do you speak only of AHA2940uw integrated on the motherboard, or about
> all such controllers (even if they're bought separately)?
The aic7xxx chips are mostly fine from a technical standpoint, but the
Linux driver (or any free driver for that matter) is not without problems.
Adaptec is very restrictive with programming information for these chips.
The driver is not good at recovering from error conditions, it has many
bugs, and it could probably be faster.
For what it's worth, I have a 3940W on one of my servers and it works
fine. The driver is still getting better every day.
Still, given Adaptec's attitude toward Linux, I will not buy any of their
products given the choice. BusLogic supports Linux hand has a fantastic,
fast, robust driver. Same goes for DPT if you need a high-end controller.
> I have one in the PCI slot (to accommodate CD writing), and am planning
> to attach Sun's SCSI disk on it.
>
> Does anybody have experiences of such configuration in work?
> Especially performance wise.
It will work. On my 3940W with a raid 0 of two IBM wide 2.2gb 7200rpm
disks, I get about 9MB/sec. If I read one disk, I get about 7MB/sec.
This is with dd and a 64k blocksize. I haven't tried these disks with
a BusLogic or DPT controller yet, so I can't comment on how good or bad
the raw throughput is.
Sooner or later I'll buy a BusLogic to replace the Adaptec card.
Thanks,
Jeff
