From owner-freebsd-hackers Tue Jul 20 15: 1:24 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id 3DAE314BE9 for ; Tue, 20 Jul 1999 15:01:20 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id PAA07726; Tue, 20 Jul 1999 15:01:18 -0700 (PDT) (envelope-from dillon) Date: Tue, 20 Jul 1999 15:01:18 -0700 (PDT) From: Matthew Dillon Message-Id: <199907202201.PAA07726@apollo.backplane.com> To: "Ronald G. Minnich" Cc: John Milford , "David E. Cross" , freebsd-hackers@FreeBSD.ORG Subject: Re: USFS (User Space File System) References: Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :On Mon, 19 Jul 1999, John Milford wrote: : :> Unless I am misunderstanding you, mfs does what you are :> describing. : :I'm pretty sure you're misunderstanding him. MFS is not even close. : :ron You know, none of us are being clear :-) The basic problem is that MFS is not a filesystem device. What you say? It looks like a filesystem device to you! Well, no. MFS is actually a *block* device that UFS runs on top of. When you create an MFS filesystem you are actually creating a UFS filesystem and running all the UFS filesystem device code, except the backing store is being implemented by MFS as a dummy block device. MFS simply copies the data to and from the VM space of the mfs process. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message