From owner-freebsd-questions Tue Mar 19 15:16:38 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id PAA09747 for questions-outgoing; Tue, 19 Mar 1996 15:16:38 -0800 (PST) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.211]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id PAA09742 for ; Tue, 19 Mar 1996 15:16:36 -0800 (PST) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id QAA25141; Tue, 19 Mar 1996 16:08:58 -0700 From: Terry Lambert Message-Id: <199603192308.QAA25141@phaeton.artisoft.com> Subject: Re: Diskless FreeBSD To: msmith@atrad.adelaide.edu.au (Michael Smith) Date: Tue, 19 Mar 1996 16:08:58 -0700 (MST) Cc: terry@lambert.org, msmith@atrad.adelaide.edu.au, amigus@cs.mun.ca, questions@freebsd.org In-Reply-To: <199603192314.JAA02655@genesis.atrad.adelaide.edu.au> from "Michael Smith" at Mar 20, 96 09:44:35 am X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-questions@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > I'm not talking about _should_, I'm talking about _is_. We run dickless > workstations here, and if you don't preallocate the swapfile, they > _don't_work_. > > I don't know _why_, I suspect that the NFS swap code doesn't/won't/can't > extend the file, but I haven't been bothered enough by it to try to find out. How can an NFS client know whether the server is zero-filling the pages or not? If you mean "extend the file", that's very different from seeking out to 20M and writing one byte (which is what I think should work). Typically, I'd say it can't extend the file because, like mmap, the vnode/extent used for cache mapping images (even for swap files) references the length from the mapping structure, not from the in core vnode. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.