From owner-cvs-all@FreeBSD.ORG Wed Oct 11 03:11:01 2006 Return-Path: X-Original-To: cvs-all@FreeBSD.org Delivered-To: cvs-all@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D1A6516A47B; Wed, 11 Oct 2006 03:11:01 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4D0C943D5D; Wed, 11 Oct 2006 03:10:59 +0000 (GMT) (envelope-from scottl@samsco.org) Received: from [192.168.254.11] (phobos.samsco.home [192.168.254.11]) (authenticated bits=0) by pooker.samsco.org (8.13.4/8.13.4) with ESMTP id k9B3An1M058707; Tue, 10 Oct 2006 21:10:55 -0600 (MDT) (envelope-from scottl@samsco.org) Message-ID: <452C60B7.1000805@samsco.org> Date: Tue, 10 Oct 2006 21:10:47 -0600 From: Scott Long User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.0.7) Gecko/20060910 SeaMonkey/1.0.5 MIME-Version: 1.0 To: Doug Ambrisko References: <200610102317.k9ANH46Z019000@ambrisko.com> In-Reply-To: <200610102317.k9ANH46Z019000@ambrisko.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-1.4 required=3.8 tests=ALL_TRUSTED autolearn=failed version=3.1.1 X-Spam-Checker-Version: SpamAssassin 3.1.1 (2006-03-10) on pooker.samsco.org Cc: src-committers@FreeBSD.org, Kip Macy , cvs-src@FreeBSD.org, cvs-all@FreeBSD.org, Kip Macy , Ceri Davies , John Birrell Subject: Re: cvs commit: src/sys/conf Makefile.sun4v files.sun4v options.sun4v src/sys/sun4v/compile .cvsignore src/sys/sun4v/conf DEFAULTS GENERIC GENERIC.hints MAC Makefile NOTES src/sys/sun4v/include _bus.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Oct 2006 03:11:01 -0000 Doug Ambrisko wrote: > Kip Macy writes: > | > | The interface is not the same - can one buy an adapter? > > True that technically the interface is not the same. The SAS connector > spans the power supply and data port. SATA has separate data and > power. However, the mechanical spacing is the same except the SAS > drive does not have the gap to fit a separate power cable and separate > data cable. I've stuck several SATA drives in a SAS backplane > enclosure and Adaptec fan out cable. The mechanical interface > precludes a SAS driver plugged into a SATA controller but the > converse is not true. The bridge between the two connectors on SAS holds the pins for the second data channel that SAS supports. At a pure electrical and signaling level, the primary channel on SAS is compatible with the single channel on SATA. But for many technical and non-technical reasons, it's possible to plug a SATA disk into a SAS connector/controller, but not the other way around. > > Do you have a SATA drive to try? I've even mixed a SAS and SATA > drives on the same controller at the same time. I know a few > people using SATA on a SAS controller since SAS drives are harder > to come by. One of the promises of SAS was that you could combine the benefit of SAS infrastructure (multipathing, channel bonding, and out-of-the-box connectivity) with the cost effectiveness of SATA. Of course, that already existed with Fibre Channel, so the migration to SAS hasn't been as swift as many had hoped. > > Now Dell doesn't recommend mixing types but I've done it to > do some testing. Even though SATA and SAS are compatible at an electrical level, there is quite a bit of magic involved in making a SAS controller talk to a SATA disk. My guess is that Dell doesn't want you adding too many magic variables to the mix on such new technology. > > There is no adapter needed :-) > > I wish there was a SCSI drive to SAS interface like PATA drive to > SATA. Unfortunately my PATA adapter is not compliant and won't > just work with a SAS cable :-( I suppose that a PATA drive should work on a SAS controller if a SATA converter is used. It's also possible to put a Chevy Nova drive train into an Audi, given enough effort with a welding torch. I just wouldn't recommend it. Scott