From owner-freebsd-current Wed Apr 24 07:27:45 1996 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id HAA17985 for current-outgoing; Wed, 24 Apr 1996 07:27:45 -0700 (PDT) Received: from who.cdrom.com (who.cdrom.com [204.216.27.3]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id HAA17962 Wed, 24 Apr 1996 07:27:38 -0700 (PDT) Received: from haldjas.folklore.ee (Haldjas.folklore.ee [193.40.6.121]) by who.cdrom.com (8.6.12/8.6.11) with ESMTP id HAA25084 ; Wed, 24 Apr 1996 07:27:20 -0700 Received: (from narvi@localhost) by haldjas.folklore.ee (8.6.12/8.6.12) id RAA19922; Wed, 24 Apr 1996 17:21:22 +0300 Date: Wed, 24 Apr 1996 17:21:22 +0300 (EET DST) From: Narvi To: "Rodney W. Grimes" cc: davidg@Root.COM, hasty@rah.star-gate.com, scrappy@ki.net, current@FreeBSD.org, hackers@FreeBSD.org Subject: Re: Intelligent Debugging Tools... In-Reply-To: <199604240832.BAA04088@GndRsh.aac.dev.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-current@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk On Wed, 24 Apr 1996, Rodney W. Grimes wrote: > > >5. make sure that one of the drives is sending the termination power > > > > For external termination, this is normally done by the controller, not any > > of the drives. > > True. > > > Most people terminate the last drive with the drive's termination > > I would disagree with that, most people use an external terminator on > an external chain. Turning terminators on inside of external scsi > enclosures is a no no in my book, it often leads to multiple termination > when someone not so informed adds something to a chain. Or middle > termination with a floating end when a chain gets swapped around. > > > and configure that drive to supply it's on termination power > ^^ own > For external scsi chains of any length > 3 feet I would _strongly_ encourage > the use of drive supplied termination power (preferably from the last > drive on the chain) to the scsi bus. > > > (which is usually the factory default). > > With the advent of the SCSI PnP spec this and other defaults are rapidly > changing, the SCSI PnP spec requires that drives ship with no termination > enabled, the use of on drive termination is verboten, you are suppose to > use cable end terminators both internally and externally. I don't seem > to recally anything about term power though :-(. There happen to be devices (at least my HP DAT is of that kind) which always supply termination power - you even can'tr turn it off. > > -- > Rod Grimes rgrimes@gndrsh.aac.dev.com > Accurate Automation Company Reliable computers for FreeBSD > Sander Eat good food, preserve nature, be nice to all nice people :)