From owner-freebsd-stable Fri Jan 29 15:24:19 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA29795 for freebsd-stable-outgoing; Fri, 29 Jan 1999 15:24:19 -0800 (PST) (envelope-from owner-freebsd-stable@FreeBSD.ORG) Received: from smtp1.jps.net (smtp1.jps.net [209.63.224.236]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA29788 for ; Fri, 29 Jan 1999 15:24:17 -0800 (PST) (envelope-from onemo@jps.net) Received: from jps.net (209-63-247-149.smf.jps.net [209.63.247.149]) by smtp1.jps.net (8.8.5/8.8.5) with ESMTP id PAA08737; Fri, 29 Jan 1999 15:24:14 -0800 (PST) Message-ID: <36B2425B.4416F26D@jps.net> Date: Fri, 29 Jan 1999 15:20:59 -0800 From: ONE-MO X-Mailer: Mozilla 4.5 [en] (X11; I; FreeBSD 3.0-STABLE i386) X-Accept-Language: en MIME-Version: 1.0 To: Wes Santee CC: freebsd-stable@FreeBSD.ORG Subject: Re: 2nd SCSI drive not detected. Why? References: <199901292318.PAA02399@bogon.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Wes Santee wrote: > And ONE-MO proclaimed... > > Do you have proper termination of the 68pin channel. Wide-SCSI is > > extremely sensitive to this and I find many people using > > Fast-SCSI without a terminator don't notice problems until they > > introduce a Wide drive into the mix. > > > > FWIW I have a 2940UW with two Ultra-Wide SCA drives using SCA to 68pin > > converter. I couldn't access the second drive unless I enabled > > termination on the second drives SCA converter. > > > > Thanks for the tips. I made sure that termination is active on both > drives since they are at either end of the SCSI bus. However, I noted > that the Wide drive has 4 termination settings (5 if you include no > termination). I'll do some research to make sure I've got the right > *kind* of termination set, just to make sure. > > Still, even with improper termination, if the SCSI bus can see the drive, > shouldn't the OS be able to? Improper termination would seem to lead to > instability, but I would still expect the OS to see it's there since > the SCSI adapter can see it. I'm just speculating here, however. > > Cheers, > -Wes No necessarily. It's the OS and application level software that is going to be sensitive to transmission timings and such. The BIOS simply polls the channel and waits fotr a response from each ID/LUN. Although termination problems *can* interfere with the card's detection, it usually shows much more prominently with the OS. MO! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message