From owner-freebsd-hackers Thu Jul 20 2: 4: 3 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id A2C1637BAA5; Thu, 20 Jul 2000 02:03:54 -0700 (PDT) (envelope-from grog@wantadilla.lemis.com) Received: (from grog@localhost) by wantadilla.lemis.com (8.9.3/8.9.3) id SAA87185; Thu, 20 Jul 2000 18:33:42 +0930 (CST) (envelope-from grog) Date: Thu, 20 Jul 2000 18:33:42 +0930 From: Greg Lehey To: Geoff Buckingham Cc: hackers@FreeBSD.ORG, scsi@FreeBSD.ORG Subject: Re: Multiple ro mounts of vinum volume Message-ID: <20000720183341.I30599@wantadilla.lemis.com> References: <20000720095513.A50799@chuggalug.clues.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0pre2i In-Reply-To: <20000720095513.A50799@chuggalug.clues.com> Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG 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. > (writing to that volume is obviously a fs issue) That depends if you want to put a file system on it. A thing that might bite you here is that ufs is currently limited to 1 TB per volume. Vinum doesn't have that restriction: if you want to create a 20 TB volume, and you know how to use the space, Vinum should work. The problem with ufs is that the block numbers in the inodes are 32 bit signed values. With 512 byte sectors, the only we can do it, that means a total address space of 2**9 * 2*31, or 1 TB. At some time I suspect we're going to need to fix that. Greg -- Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message