From owner-freebsd-fs@FreeBSD.ORG Tue Jul 17 14:44:28 2007 Return-Path: X-Original-To: freebsd-fs@freebsd.org Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 793D416A404 for ; Tue, 17 Jul 2007 14:44:28 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from moe.cs.uoguelph.ca (moe.cs.uoguelph.ca [131.104.94.198]) by mx1.freebsd.org (Postfix) with ESMTP id 20D7713C4BD for ; Tue, 17 Jul 2007 14:44:27 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from muncher.cs.uoguelph.ca (muncher.cs.uoguelph.ca [131.104.96.170]) by moe.cs.uoguelph.ca (8.13.1/8.13.1) with ESMTP id l6HEiNHY028858; Tue, 17 Jul 2007 10:44:23 -0400 Received: from localhost (rmacklem@localhost) by muncher.cs.uoguelph.ca (8.11.7p3+Sun/8.11.6) with ESMTP id l6HEmWu14892; Tue, 17 Jul 2007 10:48:32 -0400 (EDT) X-Authentication-Warning: muncher.cs.uoguelph.ca: rmacklem owned process doing -bs Date: Tue, 17 Jul 2007 10:48:32 -0400 (EDT) From: Rick Macklem X-X-Sender: rmacklem@muncher To: Eric Anderson In-Reply-To: <469CAE7D.8090609@freebsd.org> Message-ID: References: <469CAE7D.8090609@freebsd.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Scanned-By: MIMEDefang 2.57 on 131.104.94.198 Cc: freebsd-fs@freebsd.org Subject: Re: NFS on NFS? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Jul 2007 14:44:28 -0000 On Tue, 17 Jul 2007, Eric Anderson wrote: > Here's what I'd like to do: > > - Mount NFS export from filer 'A' > - Export that mountpoint to clients via NFS > > I've already tried it, and it doesn't quite work. FreeBSD allows me to > export it (doing tricks like null mounting the NFS mounted directory on a > different directory, etc). But when a client mounts it, it has issues. > > Does anyone know if this is a reasonable problem to solve for FreeBSD, or is > it so much work that it isn't worth it? > > Oh, and please - I understand the implications of doing such a thing, no > worries, I still want to. > Since this wasn't allowed for NFSv2 and 3 (due to issues such as providing a T stable file handle), clients probably won't handle it well. In general, NFSv2 and 3 clients will get really confused when the fsid or fid changes and break in subtle ways if the file handle is not T stable (refers to that file only, including long after the file is deleted). NFSv4 does allow mount point crossings (fsid to change), but some clients, such as Solaris10 are confused by it. An easier solution might be to write a simple proxy that just forwards the RPC requests/replies to the actual server. rick