From owner-freebsd-hackers Tue Dec 15 10:11:30 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id KAA29952 for freebsd-hackers-outgoing; Tue, 15 Dec 1998 10:11:30 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id KAA29946 for ; Tue, 15 Dec 1998 10:11:28 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.1/8.9.1) id KAA56534; Tue, 15 Dec 1998 10:11:15 -0800 (PST) (envelope-from dillon) Date: Tue, 15 Dec 1998 10:11:15 -0800 (PST) From: Matthew Dillon Message-Id: <199812151811.KAA56534@apollo.backplane.com> To: John Polstra Cc: eivind@yes.no, hackers@FreeBSD.ORG Subject: Re: idea/help w. mirroring References: <199812151753.JAA16545@vashon.polstra.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :Something like that would also be useful to reduce the load on :primary CVSup server hosts such as freefall. : :> Stacking layer. : :Ha ha ha, how about something that actually works, as opposed to :"sounds good in the McKusick book"? As far as I can tell, there's not :a single stackable filesystem in FreeBSD that works well enough to use :in practice. : :John :-- : John Polstra jdp@polstra.com : John D. Polstra & Co., Inc. Seattle, Washington USA : "Nobody ever went broke underestimating the taste of the American public." Hmmm. At BEST, we do a sort of stacking. We break the CVS tree out into a source tree on a read-only partition. We then construct /usr/src by 'layering' it over the read-only source tree by reconstructing the directory structure in a r+w partition and making each source file a softlink to the read-only 'backing store'. When we need to make a local hack, we break the softlink. When we update the underlying source, we diff any broken softlinks and fold in changes as appropriate. It aint perfect, but it allows us to maintain local hacks while simultaniously preventing us from accidently corrupting the source tree. -Matt Matthew Dillon Engineering, HiWay Technologies, Inc. & BEST Internet Communications & God knows what else. (Please include original email in any response) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message