From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Gilbert Subject: Re: [PATCH] minimal SAS transport class Date: Tue, 23 Aug 2005 21:10:10 +1000 Message-ID: <430B0412.4040107@torque.net> References: <9BB4DECD4CFE6D43AA8EA8D768ED51C21D7A40@xbl3.ma.emulex.com> <20050822045502.GA7147@lists.us.dell.com> <430A05F2.10009@adaptec.com> Reply-To: dougg@torque.net Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from zorg.st.net.au ([203.16.233.9]:11917 "EHLO borg.st.net.au") by vger.kernel.org with ESMTP id S932122AbVHWLKM (ORCPT ); Tue, 23 Aug 2005 07:10:12 -0400 In-Reply-To: <430A05F2.10009@adaptec.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Luben Tuikov Cc: Matt Domsch , James.Smart@Emulex.Com, hch@lst.de, jejb@steeleye.com, ltuikov@yahoo.com, Eric.Moore@lsil.com, andrew.patterson@hp.com, linux-scsi@vger.kernel.org Luben Tuikov wrote: > On 08/22/05 00:55, Matt Domsch wrote: > >>On Sat, Aug 20, 2005 at 12:15:41AM -0400, James.Smart@Emulex.Com wrote: >> >> >>>- There are some real challenges in supporting a udev-named boot >>> device. For the most part, it's a distro issue, which is becoming >>> better. PS: for $10, name a 2.6 distro that uses udev out >>> of the box for disk names and its installation. For $10 more, >>> can it install/boot from one? >> >> >>I won't get your $10, but RHEL4 has a mechanism to specify "install >>onto BIOS disk N", where N is typically 80h (it's an int13 number, >>what BIOS typically boots from). EDD in anaconda handles the mapping >>of BIOS disk number to /dev/whatever. > > > Hi Matt! How is it going? > > I wonder, do you think it would advantageous to provide > another label to a disk device which includes this mapping? > > (This is in lieu to the "myriad of labels" notion I've been > talking about recently, where vendors (BIOS, Dell, disk manufacturer, > transport layer, etc, etc, etc.) provide yet another label. This label > is tacked to the LU (most commonly a disk, it is *not* an FS label.)) > > This way, user space, or whoever, can look up the LU (disk device) > by a label, that label or whichever one. A note on the subject of LU labels: recent SCSI disks from Fujitsu, Hitachi and Maxtor (but I cannot confirm this for Seagate disks) support the REPORT and SET DEVICE IDENTIFIER SCSI commands. These use a non-volatile area outside a disk's lba space in which a user can write a label (with a max length of 16, 64 (min in current draft) or 512 (max in current draft) bytes depending on the vendor). I believe recent ATA disks also have a similar area where a disk label could be written by the OS/user. Doug Gilbert