From owner-freebsd-questions Wed Dec 17 23:04:06 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id XAA25799 for questions-outgoing; Wed, 17 Dec 1997 23:04:06 -0800 (PST) (envelope-from owner-freebsd-questions) Received: from gatekeeper.barcode.co.il (gatekeeper.barcode.co.il [192.116.93.17]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id XAA25772 for ; Wed, 17 Dec 1997 23:03:59 -0800 (PST) (envelope-from nadav@barcode.co.il) Received: (from smap@localhost) by gatekeeper.barcode.co.il (8.8.7/8.8.7) id JAA00777; Thu, 18 Dec 1997 09:00:03 +0200 (IST) (envelope-from nadav@barcode.co.il) X-Authentication-Warning: gatekeeper.barcode.co.il: smap set sender to using -f Received: from localhost.barcode.co.il(127.0.0.1) by gatekeeper.barcode.co.il via smap (V2.0) id xma000769; Thu, 18 Dec 97 08:59:46 +0200 Message-ID: <3498CAA5.5B88@barcode.co.il> Date: Thu, 18 Dec 1997 09:03:01 +0200 From: Nadav Eiron X-Mailer: Mozilla 3.0 (X11; I; SunOS 5.6 sun4u) MIME-Version: 1.0 To: amora@zoom.es CC: "John S. Dyson" , questions@FreeBSD.ORG Subject: Re: MFS related questions References: <199712162137.WAA09873@silvester.zoom.es> from "Jesus A. Mora Marin" at "Dec 16, 97 09:38:08 pm" <199712172101.WAA10767@silvester.zoom.es> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Jesus A. Mora Marin wrote: > > Thank you, John. > > > MFS performs very well in FreeBSD. Paging only happens when the > > files on the MFS filesystem get too big. There is a signficant > > design flaw that the buffer cache is synced into the MFS server, > > but that really doesn't have a severe performance hit. > > Yes, I think this point was remarked in McKusick et al's book (pp 305 > & 306). It seems this flaw was a result of the virtual memory system > implementation when MFS was originally designed. > > Well, I have thought further about this subject and guess that the > MFS_ROOT specifies the size of the mfs root directory when mounted, > but I assume this value can be overridden by actual parameters in the > mfs_mount command. > No. MFS_ROOT is an option to make the root filesystem (i.e. /) an MFS system, whose content is compiled into the kernel. See the section in the handbook about making a bootable floppy (somewhere under backup) for the details. This is how the installation floppy works. > One last question: how many mfs filesystems can be mounted at any > time? > > Jesus > ------ > Jesus A. Mora Marin, MD. (aka EA7HAC, ex-EC7DVE) Nadav