Return-Path: Received: from mail-ew0-f226.google.com ([209.85.219.226]:50818 "EHLO mail-ew0-f226.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751268Ab0AWQ1k convert rfc822-to-8bit (ORCPT ); Sat, 23 Jan 2010 11:27:40 -0500 Received: by ewy26 with SMTP id 26so437585ewy.28 for ; Sat, 23 Jan 2010 08:27:39 -0800 (PST) In-Reply-To: <1f808b4a1001230757i2027d32dxb48482ea7bf8e4ee@mail.gmail.com> References: <1f808b4a1001230757i2027d32dxb48482ea7bf8e4ee@mail.gmail.com> Date: Sat, 23 Jan 2010 17:27:38 +0100 Message-ID: Subject: Re: nfs client performance while server is down From: Whoop Whouzer To: Peter Chacko Cc: linux-nfs@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 I don't remember all the different set-ups I tried it on, but I just confirmed this with the following combinations: ubuntu server 10.04 (alpha 2) --> ubuntu desktop 9.10, ubuntu desktop 10.04 (alpha 2), fedora 12 ubuntu server 9.10 --> ubuntu desktop 9.10, ubuntu desktop 10.04 (alpha 2), fedora 12 I'll be happy to test it on another client machine (distro) even another server (although it would require a little more time) Here are some examples on the bugreports I noticed and how they do not seem to get solved: https://bugzilla.redhat.com/show_bug.cgi?id=175283 https://bugs.launchpad.net/ubuntu/+source/nfs-utils/+bug/164120 regards, Whoop On Sat, Jan 23, 2010 at 4:57 PM, Peter Chacko wrote: > Which client OS you observed this behavior ? ?This has nothing to do > NFS design, and its purely stateless...Its upto the client OS > implementation about aspects like how to deal with local IO, when NFS > share gets ?disconnected.. > > May be a VFS bug on the local OS you found this problem .. > > thanks > > On Sat, Jan 23, 2010 at 9:15 PM, Whoop Whouzer wrote: >> Howdy, >> >> I was wondering why nfs is designed in such a way that the performance >> of an nfs client machine gets very bad when the nfs server is offline? >> This is even the case with a soft mount (either via mount or fstab). >> Just about every application that requires disk access (not talking >> about nfs share acces) gets really slow to unresponsive. For instance >> nautilus becomes unresponsive when displaying the contents of any >> folder on the local disk, >> playing movie files (stored on local disk) let totem or vlc get stuck >> on set intervals, even the terminal becomes unresponsive at times. >> >> I could understand that these problems would occur while accessing the >> nfs share directoiourry while the server is offline, but why for totally >> unrelated directories? >> >> I have experienced this behaviour on various distro's, and also found >> various bug reports on this issue, they don't seem to get solved as >> this is viewed as nfs design. >> I see this as a flaw because clients are totally dependent on the >> server. This would be less of a deal if the entire home directory >> would be stored on nfs (although I even think some sort of >> synchronisation technology could and should be implemented in this >> case). It is a bit odd that (technically) one machine serving some >> "useless" files to a non-trivial directory on client machines can take >> down these client machines. >> >> For me the preferred functionality would be: >> *If an nfs server gets offline the client's nfs share becomes >> unaccessible, but local directories and applications (that only >> require local disk access) stay responsive. >> *If an nfs server gets online (after being offline while the client >> has not been restarted) the nfs share becomes reconnected. >> >> regards, >> Whoop >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at ?http://vger.kernel.org/majordomo-info.html >> >