From owner-freebsd-current@FreeBSD.ORG Wed Apr 20 23:36:00 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BB0BA1065675; Wed, 20 Apr 2011 23:36:00 +0000 (UTC) (envelope-from mj@feral.com) Received: from ns1.feral.com (ns1.feral.com [192.67.166.1]) by mx1.freebsd.org (Postfix) with ESMTP id 2A6268FC18; Wed, 20 Apr 2011 23:36:00 +0000 (UTC) Received: from ns1.feral.com (localhost [127.0.0.1]) by ns1.feral.com (8.14.4/8.14.4) with ESMTP id p3KNZxmu094471 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 20 Apr 2011 16:35:59 -0700 (PDT) (envelope-from mj@feral.com) Received: from localhost (mjacob@localhost) by ns1.feral.com (8.14.4/8.14.4/Submit) with ESMTP id p3KNZwSb094468; Wed, 20 Apr 2011 16:35:59 -0700 (PDT) (envelope-from mj@feral.com) X-Authentication-Warning: ns1.feral.com: mjacob owned process doing -bs Date: Wed, 20 Apr 2011 16:35:58 -0700 (PDT) From: Matthew Jacob To: Scott Long In-Reply-To: Message-ID: References: <4DAEAE1B.70207@FreeBSD.org> <20110420203754.GM85668@acme.spoerlein.net> <4DAF46F8.9040004@FreeBSD.org> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (ns1.feral.com [127.0.0.1]); Wed, 20 Apr 2011 16:35:59 -0700 (PDT) Cc: FreeBSD-Current , Alexander Motin Subject: Re: Switch from legacy ata(4) to CAM-based ATA X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Matthew Jacob List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Apr 2011 23:36:00 -0000 On Wed, 20 Apr 2011, Scott Long wrote: >... > > I agree with what Alexander is saying, but I'd like to take it a step > further. We should all be using either mount-by-label, or be working to > introduce generic device names to GEOM. Right now, device names are an > implementation detail that have no functional use other than to > complicate the fstab. Disks exposed through the block layer are simply > direct-access block-array devices, nothing more. There's no functional > difference to the kernel or userland between ad, ar, da, aacd, mfid, > amrd, etc when it comes to reading and writing sectors off of them. > But yet we give them unique names and pretend that those names mean > something. We could give them all the name of "disk" and the system > would still function exactly that same. The name attributes are > interesting when it comes to doing out-of-band management, but it's also > trivial to create a human-readable map and a programatic API between the > generic name and the attribute name. Same goes for volumes labels, and > I'd almost argue that they're more powerful than generic device names. > > In other words, "ada" isn't the problem here, it's that we all still > think in terms of the 1980's when systems didn't autoconfigure and > device names were important hints to system functionality. That time > has thankfully passed, and it's time for us to catch up. > Still, keep in mind that conservative leanings have to be appeased. Back in SparcStation1 development (1989) we kept on calling the root device "Fred" as in "Let's boot fred now". That said, you would not *believe* the flack I took for having the root filesystem on sd3 instead of sd0 in SS1, even though there was no reason it couldn't have just been called "fred".