Date: Mon, 24 Jul 2000 16:31:41 -0600 From: "Kenneth D. Merry" <ken@kdm.org> To: Matthew Jacob <mjacob@feral.com> Cc: Poul-Henning Kamp <phk@critter.freebsd.dk>, Jack Rusher <jar@integratus.com>, freebsd-arch@FreeBSD.ORG Subject: Re: SANs, disks, & devfs Message-ID: <20000724163141.A58251@panzer.kdm.org> In-Reply-To: <Pine.BSF.4.05.10007241419380.15581-100000@semuta.feral.com>; from mjacob@feral.com on Mon, Jul 24, 2000 at 02:25:32PM -0700 References: <6890.964465587@critter.freebsd.dk> <Pine.BSF.4.05.10007241419380.15581-100000@semuta.feral.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jul 24, 2000 at 14:25:32 -0700, Matthew Jacob wrote: > > Well, this doesn't address directly things like tape devices or ses instances > (e.g.)- basically anything that is SCSI or Fibre Channel addressable has some > kind of WWN or Serial Number for the device itself, but there is more or less > general consensus from linux to Veritas to here that an ondisk label (past > initial import) is the right thing to do. > > Again- I think that this and the full devfs is a usable methodology. I still > would like some feedback as to whether or not linking mount (and mt, e.g.) > with libcam so I can use device VPD info or WWNs would be just too awful for > FreeBSD. This way it can be used now, without vinum. I think that might be good for a first shot at it, but it might be nice to eventually have a way of dealing with more than just CAM-attached devices. e.g., you could have some sort of generic kernel registry/database/list that each peripheral driver instance would register itself with, along with a serial number of some sort. da0 would register its serial number of ABC138557232, and da1 would register its serial number of XyZ138475393, and ad0 would register its serial number of XLP83733312. You could have a name located in the disklabel take precendence over an in-disk serial number if it is present, and possibly have an automatically generated serial number to name table that is loaded in by the loader. So you could have a name for your tape drive, even though you can't put a disklabel on it. (Such a table might be generated by sysinstall, or by some other program.) You'd probably also want to have a way to include positional information as a qualifying argument for the case where you have more than one device with identical identifiers. So if you had two disks with the name "Fred" in the disklabel, you would need to call one "Fred@scbus0:1:0" and the other "Fred@scbus1:3:0". If you had two identical disklabel names, you could conceivably qualify them by the disk serial number, if available, but otherwise you'd have to fall back on the positional information. Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000724163141.A58251>