From owner-freebsd-questions Tue Feb 11 14:18:16 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id OAA23448 for questions-outgoing; Tue, 11 Feb 1997 14:18:16 -0800 (PST) Received: from gdi.uoregon.edu (gdi.uoregon.edu [128.223.170.30]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id OAA23443 for ; Tue, 11 Feb 1997 14:18:13 -0800 (PST) Received: from localhost (dwhite@localhost) by gdi.uoregon.edu (8.8.5/8.6.12) with SMTP id OAA00548; Tue, 11 Feb 1997 14:17:51 -0800 (PST) Date: Tue, 11 Feb 1997 14:17:50 -0800 (PST) From: Doug White X-Sender: dwhite@localhost Reply-To: Doug White To: "K.J.Koster" cc: freebsd-questions@freebsd.org Subject: Re: MFS config and disk usage In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-questions@freebsd.org X-Loop: FreeBSD.org Precedence: bulk On Tue, 11 Feb 1997, K.J.Koster wrote: > I though I understood how MFS uses diskspace, but I was wrong. Please help > me out. MFS using diskspace is an oxymoron. MFS = memory filesystem. > I have two swap partitions, one on /dev/sd0s2b and one on /dev/sd1s2b, > each about 50Mb. Since I wanted to use MFS (very large performance > increase!), I mounted the /dev/sd1s2b partition as an MFS disk on /tmp, > leaving /dev/sd0s2b as a normal swap partition. This works fine and fast. > > Trouble starts when I put substantial amounts of stuff in /tmp. As far as > I can make out, mount_mfs process grows to 50Mb as /tmp fills up, eating > my swap space. That's what's supposed to happen. > My question (finally) is: Why do I give mount_mfs the 50Mb /dev/sd1s2b > partition, if that disk space is not used to swap the information into? Are you trying to mount this memory space as SWAP or /tmp? You have it mounted as /tmp, using the traditional swap partition (b). You can't have both. > How can I best combine the two swap partitions and an MFS disk? Is there a > way that I can explain to mount_mfs that it can use all available swap > space, and have both /dev/sd0s2b and /dev/sd1s2b as swap partitions? Save the swap for disks. Making MFS swap is doing memory->memory transfers and isn't helping you at all, in fact it's hurting you. Use the MFS for /tmp space if you're finding your system pounds on it a bunch. Naturally, if you put a limit on the MFS that's greater than physical memory, it'll swap, and your system will come to a screeching halt. I'm not that experienced with MFSs (I don't use them), but I'd think you'd want it's max size < max available memory. Doug White | University of Oregon Internet: dwhite@resnet.uoregon.edu | Residence Networking Assistant http://gladstone.uoregon.edu/~dwhite | Computer Science Major