Return-Path: Received: from mail2.shareable.org ([80.68.89.115]:56035 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751774Ab0CITf7 (ORCPT ); Tue, 9 Mar 2010 14:35:59 -0500 Date: Tue, 9 Mar 2010 19:35:45 +0000 From: Jamie Lokier To: Brad Boyer Cc: Casey Schaufler , James Morris , linux-nfs@vger.kernel.org, linux-security-module@vger.kernel.org, Trond Myklebust , "J. Bruce Fields" , Neil Brown , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 0/6][v4][RFC] NFSv3: implement extended attribute protocol (XATTR) Message-ID: <20100309193545.GE11042@shareable.org> References: <20100309035932.GA14237@cynthia.pants.nu> <4B95E167.40306@schaufler-ca.com> <20100309070444.GA18216@cynthia.pants.nu> Content-Type: text/plain; charset=us-ascii In-Reply-To: <20100309070444.GA18216@cynthia.pants.nu> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Brad Boyer wrote: > On Mon, Mar 08, 2010 at 09:49:27PM -0800, Casey Schaufler wrote: > > Another is to NFS mount the filesystem back on to the server, > > in which case James' scheme works just dandy. It's a trick that > > I've used more than once in the Unix world for this exact purpose. > > Of course you have to arrange your mount points in advance with > > malice aforethought, but that's likely something you're used to > > by now. > > That would definitely work, but it's not ideal. Obviously if it's > being accessed over NFS in one place it probably good enough > everywhere, but it's overhead that could be eliminated. As a real example: Each user has a PC with their own home directory being local, fast storage, but /home is filled with NFS auto-mounts to everyone else's home directories, on their individual PCs. The auto-mount map has an exception, so the local user's home directory is a symlink to the local storage, instead of an NFS mount. A scheme like that works very well for occasional access to other peoples files, and for logging to each other's machines transparently, yet having fast performance for their own files when using their local machine. In an environment where I've used that, forcing local access to go over local NFS would have destroyed performance for things like big compiles, running find, git, grep etc. that people do on their own directories. -- Jamie