Date: Sun, 01 Aug 2004 15:09:16 +0100 From: Pete French <petefrench@ticketswitch.com> To: m.seaman@infracaninophile.co.uk, mg-fbsd3@grant.org Cc: petefrench@ticketswitch.com Subject: Re: How does CAM determine the order to number drives ? Message-ID: <E1BrH1Y-000OlQ-H5@dilbert.firstcallgroup.co.uk> In-Reply-To: <20040731203018.GA75175@happy-idiot-talk.infracaninophile.co.uk>
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> You can wire down particular devices to a given SCSI bus, target and
> LUN. Thus in your (4.x) kernel config you can say:
>
> device scbus0 at ahc0
> device da0 at scbus0 target 0 unit 0
Thanks for this - it looked as though it was just what I needed. I built
a kernel with scbus0 placed at ahc? (ahc0 would not compile - but I only
have one Adaptec controller in the machine). I would have thought this
was sufficient as it would then scan scbus0 first and thus find the
Addapted conntected drive first. But it did not appear to do this - I
still had the ciss drives appearing first.
I assume for this that the second line is also necessary (which
surprises me), but at this point I had the lid of the machine
off so I simply moved cards around until the Adaptec was scanned
first by the kernel on startup. Which seemed simpler than putting
all the old controllers back and compiling yet another kernel :-)
But thanks for all the advice, (even if I didnt follow it to the letter
in the end). Very useful to know.
-pcf.
PS: For anyone interested in making a similar upgrade, the performance
increase of the 5300 over the 4200 is very impressive. Around 65%
on read performances from RAID-0+1 and 50% from RAID-5. Whether thats
due to the change of BSD driver as well as the change of controller I
don't know, but I am very happy with it!
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