Subject: Re: Help - don't understand SATA!
To: Perry E. Metzger <perry@piermont.com>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: netbsd-users
Date: 10/06/2005 15:36:50
On Thu, Oct 06, 2005 at 01:28:56PM -0400, Perry E. Metzger wrote:
> 
> Luke Mewburn <lukem@NetBSD.org> writes:
> > I used to use Adaptec and 3ware IDE RAID cards in my file server.
> > Now I use RAIDframe again (on ATA & SATA disks).
> 
> Speaking of RAIDframe, if one wants to build a big RAIDframe array of
> SATA drives one needs a plain old SATA disk controller that will
> handle a lot of drives which NetBSD will support. Does anyone have a
> recommendation for a such a controller? I haven't been able to find
> anything decent after a quick search...

It depends how many slots you have available.  4-port cards are pretty
common (SiiG makes one that uses the SiI 3114, which works well) and
many motherboards have 2, 4, or even 6 onboard SATA ports.  So, if
you're putting a lot of disks into a big chassis, you can get into
the 16-20 port range without too much trouble.

I don't know of any cards with more than 4 ports that just expose the
disks as plain ATA disks.  However, there are several RAID cards that
have many SATA ports -- the 3ware cards, the Adaptec cards, the LSI
cards -- and you can run them in JBOD mode and RAIDframe the disks,
and it may well be that you get better performance that way.

The hub-and-spoke stuff from SATA II would be *really* nice for this
kind of application, but the original poster is right: we can't support
it without some driver work, and it _may_ not work at all with SATA I
disks; I would very much like to know if it would.

-- 
 Thor Lancelot Simon	                                      tls@rek.tjls.com

"The inconsistency is startling, though admittedly, if consistency is to be
 abandoned or transcended, there is no problem."		- Noam Chomsky