From owner-freebsd-geom@FreeBSD.ORG Thu Jul 9 20:00:57 2009 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EFCD0106566C for ; Thu, 9 Jul 2009 20:00:57 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (chello087206192061.chello.pl [87.206.192.61]) by mx1.freebsd.org (Postfix) with ESMTP id 48AC38FC16 for ; Thu, 9 Jul 2009 20:00:56 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id F018845C89; Thu, 9 Jul 2009 22:00:54 +0200 (CEST) Received: from localhost (chello087206192061.chello.pl [87.206.192.61]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id A83BD45683; Thu, 9 Jul 2009 22:00:49 +0200 (CEST) Date: Thu, 9 Jul 2009 22:01:02 +0200 From: Pawel Jakub Dawidek To: Ivan Voras Message-ID: <20090709200102.GA2438@garage.freebsd.pl> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="gBBFr7Ir9EOA20Yy" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 8.0-CURRENT i386 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-0.6 required=4.5 tests=BAYES_00,RCVD_IN_SORBS_DUL autolearn=no version=3.0.4 Cc: freebsd-geom@freebsd.org Subject: Re: glabel and real disk IDs X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Jul 2009 20:00:58 -0000 --gBBFr7Ir9EOA20Yy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 09, 2009 at 01:52:53PM +0200, Ivan Voras wrote: > Hi, >=20 > I've been working with glabels for a time [...] You should stop, really. We have enough labels in /dev/ as it is. > [...] and just remembered that ATA=20 > (ad) drives do in fact export the drive ID, for example: >=20 > # diskinfo -v ad4 > ad4 > 512 # sectorsize > 320072933376 # mediasize in bytes (298G) > 625142448 # mediasize in sectors > 620181 # Cylinders according to firmware. > 16 # Heads according to firmware. > 63 # Sectors according to firmware. > ad:9QF4H15Y # Disk ident. >=20 > # diskinfo -v ad6 > ad6 > 512 # sectorsize > 320072933376 # mediasize in bytes (298G) > 625142448 # mediasize in sectors > 620181 # Cylinders according to firmware. > 16 # Heads according to firmware. > 63 # Sectors according to firmware. > ad:9QF4EP7A # Disk ident. >=20 > # diskinfo -v ad8 > ad8 > 512 # sectorsize > 320072933376 # mediasize in bytes (298G) > 625142448 # mediasize in sectors > 620181 # Cylinders according to firmware. > 16 # Heads according to firmware. > 63 # Sectors according to firmware. > ad:9QF4H16L # Disk ident. >=20 > I don't think it would be hard to add a label parser to gather this=20 > information and export it as a label. It was proposed in the past and the consensus was not to do it. One of the reasons was polution of /dev/, another one was that the way of getting SCSI disks IDs was not perfect. > The purpose of this would be to have a unique disk ID without explicitly= =20 > setting a label (e.g. as is commonly advised for ZFS and drive swapping). I guess you advice that? There is no such need when it comes to ZFS. ZFS can find his components just fine without using their names. Disk IDs were added for ZFS in the past, but now they serve no purpose, I'd prefer to remove them altogether or just leave them for informational purpose as they exist now. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --gBBFr7Ir9EOA20Yy Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFKVkx+ForvXbEpPzQRAl8gAKCZFUl3Zr9k9pOs6DqLOhuuc3mecQCfZ+7u bRpziQP+8YJpIdiCF/98Jd0= =di1Y -----END PGP SIGNATURE----- --gBBFr7Ir9EOA20Yy--