From: Ian Kent Subject: Re: [NFS] making the 'addr=' mount option an address hint Date: Tue, 19 Jul 2005 20:17:27 +0800 (WST) Message-ID: References: <1121614708.6713.41.camel@localhost.localdomain> <1121700961.8780.13.camel@lade.trondhjem.org> <1121711065.23863.31.camel@barsoom.rdu.redhat.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: autofs@linux.kernel.org, nfs@lists.sourceforge.net, Trond Myklebust Return-path: To: Jeff Layton In-Reply-To: <1121711065.23863.31.camel@barsoom.rdu.redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: autofs-bounces@linux.kernel.org Errors-To: autofs-bounces@linux.kernel.org List-ID: On Mon, 18 Jul 2005, Jeff Layton wrote: > On Mon, 2005-07-18 at 11:36 -0400, Trond Myklebust wrote: > > There's nothing preventing it from working, but what is stopping you > > from developing a fully automatic version? > > Nothing is stopping that, but if we're going to do so much in the mount > program, there's probably no point in doing all of this in autofs. Why > do RPC pings at all in autofs if we're going to turn right around and do > them again in the mount program? For mounting over a WAN (for instance) > the ping checks could really add up to a substantial delay in mounting. If I remember correctly, there were two reasons that this was done in autofs, one was that mount used to hang when machines couldn't be reached. The second was to support replicated server mount syntax. Mount may not hang anymore with introduction of probing but it doesn't support the replicated server syntax. The other problem with mounts' probing is that it's quite aggressive, opening, it appears, more sockets than it really needs to. > > For now, I'd like to keep my initial patch somewhat small and simple and > simply make the addr= option be respected, but I'd certainly consider > redoing it to add the stuff you mention above at a later time. > > My suggestion would be to consider this in conjunction with autofs v5 > (or a later v4 version) so we don't end up duplicating so much > functionality. You'll need to get in quick ito those sort of changes in v5. As I said, to persue the probing logic we really need to add some simple, single socket per server multiplexing at least, to thr RPC layer. Ian