From owner-freebsd-hackers Thu Aug 31 10:20:14 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.FreeBSD.org (8.6.11/8.6.6) id KAA13741 for hackers-outgoing; Thu, 31 Aug 1995 10:20:14 -0700 Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.211]) by freefall.FreeBSD.org (8.6.11/8.6.6) with ESMTP id KAA13729 for ; Thu, 31 Aug 1995 10:20:09 -0700 Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id KAA22960; Thu, 31 Aug 1995 10:15:54 -0700 From: Terry Lambert Message-Id: <199508311715.KAA22960@phaeton.artisoft.com> Subject: Re: can swap space be shared with other OSes? To: leisner@sdsp.mc.xerox.com (Marty Leisner) Date: Thu, 31 Aug 1995 10:15:54 -0700 (MST) Cc: freebsd-hackers@FreeBSD.ORG In-Reply-To: <9508311508.AA29077@gnu.mc.xerox.com> from "Marty Leisner" at Aug 31, 95 08:08:03 am X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1897 Sender: hackers-owner@FreeBSD.ORG Precedence: bulk > While I'm working with partitions, I also want to be able to recognize > bsd disk slices as several devices (and perhaps port a ffs driver to > linux). (I already hacked up the linux fdisk to recognize bsd partitions). > > Can the swap space for bsd be shared by bsd/windows/linux? > > There's a strategy for sharing swap space on linux/windows... There's a similar one for BSD: mount the DOS drive, configure a vn device using vnconfig, and use it as swap. I believe a similar scheme would work for an unknown partition ID, for instance the Linux swap -- assuming each DOS partition gets a logical device regardless of whether we recognize the ID or not. This is something that should be done if it hasn't been already. This is more an algorithmic issue for devfs than anything else; the idea of a major (controller) and minor (target) number is based on the idea that you get a vnode that points to the device. If you have a devfs, you can get one of these without a major or a minor: the device is exported by vnode intrinsically, so the structure reference can be hard coded without a major or a minor for each device exported. This is an important prerequisite for cloning pty devices, for instance, though one doesn't strictly need a devfs if one can hack the lookup routines based on the major (what AIX does). > Also, is there interest in getting an ext2 driver on freebsd (to read > linux partitions). I believe someone is working on this and recently reported some success to the -current list (that might have been you, though, so if it was, then "yes!"). > I think the key to running multiple OSes is easy interoptability (even > if the drivers are only read only). Agree -- though read-only is semi-operable, not interoperable. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.