From owner-freebsd-scsi Thu Jul 20 2:32: 5 2000 Delivered-To: freebsd-scsi@freebsd.org Received: from chuggalug.clues.com (chuggalug.clues.com [194.217.82.22]) by hub.freebsd.org (Postfix) with ESMTP id 0714437B625; Thu, 20 Jul 2000 02:32:00 -0700 (PDT) (envelope-from geoffb@chuggalug.clues.com) Received: (from geoffb@localhost) by chuggalug.clues.com (8.9.3/8.9.3) id KAA50932; Thu, 20 Jul 2000 10:31:50 +0100 (BST) (envelope-from geoffb) Date: Thu, 20 Jul 2000 10:31:50 +0100 From: Geoff Buckingham To: Greg Lehey Cc: hackers@FreeBSD.ORG, scsi@FreeBSD.ORG Subject: Re: Multiple ro mounts of vinum volume Message-ID: <20000720103150.A50907@chuggalug.clues.com> References: <20000720095513.A50799@chuggalug.clues.com> <20000720183341.I30599@wantadilla.lemis.com> <20000720183812.K30599@wantadilla.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i In-Reply-To: <20000720183812.K30599@wantadilla.lemis.com>; from Greg Lehey on Thu, Jul 20, 2000 at 06:38:13PM +0930 Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Thu, Jul 20, 2000 at 06:38:13PM +0930, Greg Lehey wrote: > On Thursday, 20 July 2000 at 18:33:42 +0930, Greg Lehey wrote: > > On Thursday, 20 July 2000 at 9:55:13 +0100, Geoff Buckingham wrote: > >> > >> Does anybody with a knowledge of the vinum code have an opinion on > >> the amount of work involved in getting vinum to the point that > >> several JBODs in a FC switched fabric could be managed, as a vinum > >> volume, by one machine, and mounted ro by that machine and several > >> others on the switch fabric. > > > > I'd say "no work at all" as far as Vinum is concerned. The real issue > > is getting the drivers to present the individual drives to the > > system. That's a device driver issue, and I don't know enough about > > the current state of FC drivers to make a sensible comment. But I'd > > certainly be interested to hear more. > > I believe all the disks should be visable to all the hosts, unless some aspect of your switch fabric has been configured to hide disks from NT4 boxes. > >> (writing to that volume is obviously a fs issue) > > Oops, I missed the point here. Yes, the multiple R/O issue would make > it very difficult to write to it. I suspect that it would be almost > impossible to write while other systems had the volume open R/O. I'll > think about how that could be done, but it's not simple, if it's at > all possible. > I would be happy with unmounting the FS everywhere mounting it rw on the 'management' machine , writing, then reversing back to having it mounted ro everywhere. I may have a play with this in a few months when I have a bit more kit, as I had imagined there would be more issues with multiple machines, each with an instance of vinum trying to manage the same single volume (particulary in degraded or repair situations) On the Fs front I must confess to having lost track of the XFS situation/ devate after the intial storm of interest when SGI first announced their interest. What happened? -- GeoffB To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message