From owner-freebsd-questions Wed Feb 9 0:56: 2 2000 Delivered-To: freebsd-questions@freebsd.org Received: from dorifer.heim3.tu-clausthal.de (dorifer.heim3.tu-clausthal.de [139.174.243.252]) by builder.freebsd.org (Postfix) with ESMTP id 84E683E25 for ; Wed, 9 Feb 2000 00:55:56 -0800 (PST) Received: (from olli@localhost) by dorifer.heim3.tu-clausthal.de (8.9.3/8.9.3) id JAA49968; Wed, 9 Feb 2000 09:40:06 +0100 (CET) (envelope-from olli) Date: Wed, 9 Feb 2000 09:40:06 +0100 (CET) Message-Id: <200002090840.JAA49968@dorifer.heim3.tu-clausthal.de> From: Oliver Fromme To: freebsd-questions@FreeBSD.ORG Reply-To: freebsd-questions@FreeBSD.ORG Subject: Re: memory filesystem X-Newsgroups: list.freebsd-questions In-Reply-To: <877803$2ot7$1@atlantis.rz.tu-clausthal.de> User-Agent: tin/1.4.1-19991201 ("Polish") (UNIX) (FreeBSD/3.4-19991219-STABLE (i386)) MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Chad David wrote in list.freebsd-questions: > I have a need to create a memory filesystem > on a system that boots from a CD. That means > that besides a floppy, I have no writable media, > and therefore, no swap. > [...] > and MFS seems to require a writable block device. Such as /dev/zero. :-) The only thing mfs_mount needs a device for is to find out the disk type and size of the partition. If you specify the size with -s and the disk type with -T (which can be any entry from your /etc/disktab, such as "minimum" which is always present), then you can simply use /dev/zero as device. It will simply be ignored by mount_mfs. So, for example, your /etc/fstab entry could look like this: /dev/zero /tmp mfs rw,nosuid,-s=64000,-m=0,-T=minimum 0 0 We're using the above entry on our diskless websurf terminals, which mount the whole system read-only via NFS, so we need a small writable MFS for a few things, too. Works great. Regards Oliver -- Oliver Fromme, Leibnizstr. 18/61, 38678 Clausthal, Germany (Info: finger userinfo:olli@dorifer.heim3.tu-clausthal.de) "In jedem Stück Kohle wartet ein Diamant auf seine Geburt" (Terry Pratchett) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message