From owner-freebsd-hackers Tue Aug 17 14: 6:21 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from sv01.cet.co.jp (sv01.cet.co.jp [210.171.56.2]) by hub.freebsd.org (Postfix) with ESMTP id AD45B157DF; Tue, 17 Aug 1999 14:06:01 -0700 (PDT) (envelope-from michaelh@cet.co.jp) Received: from localhost (michaelh@localhost) by sv01.cet.co.jp (8.9.3/8.9.3) with SMTP id VAA18756; Tue, 17 Aug 1999 21:05:08 GMT Date: Wed, 18 Aug 1999 06:05:08 +0900 (JST) From: Michael Hancock To: Bill Studenmund Cc: Terry Lambert , Hackers@FreeBSD.ORG, fs@FreeBSD.ORG Subject: Re: BSD XFS Port & BSD VFS Rewrite In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > Have you tried Heidemann's student's stacking layers? There is one > > encryption, and one per-file compression with namespace hiding, that > > I think it would be hard pressed to keep up with. But I'll give it > > the benefit of the doubt. 8-). > > Nope. The problem is that while stacking (null, umap, and overlay fs's) > work, we don't have the coherency issues worked out so that upper layers > can cache data. i.e. so that the lower fs knows it has to ask the uper > layers to give pages back. :-) But multiple ls -lR's work fine. :-) Interesting, have you read the Heidemann paper that outlines a solution that uses a cache manager? You can probably find it somewhere here, http://www.isi.edu/~johnh/SOFTWARE/UCLA_STACKING/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message