From owner-freebsd-hackers Tue Jul 9 15:38: 3 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1F9D237B400 for ; Tue, 9 Jul 2002 15:38:01 -0700 (PDT) Received: from panzer.kdm.org (panzer.kdm.org [216.160.178.169]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4920A43E09 for ; Tue, 9 Jul 2002 15:38:00 -0700 (PDT) (envelope-from ken@panzer.kdm.org) Received: from panzer.kdm.org (localhost [127.0.0.1]) by panzer.kdm.org (8.12.5/8.12.5) with ESMTP id g69MbxKi075798; Tue, 9 Jul 2002 16:37:59 -0600 (MDT) (envelope-from ken@panzer.kdm.org) Received: (from ken@localhost) by panzer.kdm.org (8.12.5/8.12.5/Submit) id g69MbxvF075797; Tue, 9 Jul 2002 16:37:59 -0600 (MDT) (envelope-from ken) Date: Tue, 9 Jul 2002 16:37:59 -0600 From: "Kenneth D. Merry" To: Keith Pitcher Cc: freebsd-hackers@freebsd.org Subject: Re: [hackers] Multi CDR burn Message-ID: <20020709163758.A75775@panzer.kdm.org> References: <20020708220105.GA32341@stone.locallink.net> <15658.50186.945164.162061@canoe.velocet.net> <20020709191404.GA97352@stone.locallink.net> <15659.17952.903580.570415@canoe.velocet.net> <20020709161015.A75408@panzer.kdm.org> <20020709222716.GA21856@stone.locallink.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20020709222716.GA21856@stone.locallink.net>; from kpitcher@locallink.net on Tue, Jul 09, 2002 at 06:27:16PM -0400 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Tue, Jul 09, 2002 at 18:27:16 -0400, Keith Pitcher wrote: > > > I also didn't know that there was a write-to-many SCSI command? > > > Someone can confirm or deny this > > Coulda sworn the raid controller on our main freebsd machine does mirroring > via scsi with a single command. So I took it that this was a scsi card ability > and not a raid controller option. You send a single command to the RAID controller, but it will send a command to each disk in the mirror on a write. > I did a real quick search of the scsi spec and came across the > "Single Initiator - Multiple Targets" ability but this may > not mean what I take it to mean. It doesn't mean you can talk to multiple targets simultaneously. Just that with one SCSI initiator, you can talk to multiple targets one at a time. With SAS (Serial Attached SCSI) that may change, since SAS is inherently a point to point protocol. Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message