From: Whoop Whouzer Subject: Re: nfs client performance while server is down Date: Mon, 25 Jan 2010 01:09:12 +0100 Message-ID: References: <1f808b4a1001230757i2027d32dxb48482ea7bf8e4ee@mail.gmail.com> <7A24DF798E223B4C9864E8F92E8C93EC0527810C@SACMVEXC1-PRD.hq.netapp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Peter Chacko , linux-nfs@vger.kernel.org To: "Muntz, Daniel" Return-path: Received: from mail-ew0-f226.google.com ([209.85.219.226]:40145 "EHLO mail-ew0-f226.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751398Ab0AYAJP convert rfc822-to-8bit (ORCPT ); Sun, 24 Jan 2010 19:09:15 -0500 Received: by ewy26 with SMTP id 26so1711559ewy.28 for ; Sun, 24 Jan 2010 16:09:13 -0800 (PST) In-Reply-To: <7A24DF798E223B4C9864E8F92E8C93EC0527810C-hX7t0kiaRRpT+ZUat5FNkAK/GNPrWCqfQQ4Iyu8u01E@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: I did some network traces and there is nothing strange happening as far as I can tell. I shut down the server (some network traffic occurred as is to be expected). It got quiet again, I launched nautilus, it got stuck without displaying anything and there was no real network activity except 3 broadcasts using the ARP protocol asking where the server was (could be just coincidence). Closing nautilus and launching it again will let it hang again but I see no additional network traffic. After a while nautilus will display the contents of the folder without any network traffic. On Sun, Jan 24, 2010 at 10:34 PM, Muntz, Daniel = wrote: > Perhaps something in your $PATH is in the NFS mount? =A0Do a network = trace and maybe you can see if, in fact, there are actually NFS operati= ons being attempted that you weren't expecting. =A0Then try to figure o= ut why. > > =A0-Dan > >> -----Original Message----- >> From: Whoop Whouzer [mailto:tiredandnumb@gmail.com] >> Sent: Saturday, January 23, 2010 8:28 AM >> To: Peter Chacko >> Cc: linux-nfs@vger.kernel.org >> Subject: Re: nfs client performance while server is down >> >> 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 deskto= p >> 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 n= ot >> seem to get solved: >> https://bugzilla.redhat.com/show_bug.cgi?id=3D175283 >> 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 ? =A0This has nothing t= o 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 =A0disconnected.. >> > >> > 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 talki= ng >> >> 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= =2E >> >> >> >> 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 thi= s >> >> case). It is a bit odd that (technically) one machine serving som= e >> >> "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 clie= nt >> >> 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 =A0http://vger.kernel.org/majordomo-info.h= tml >> >> >> > >> -- >> 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 =A0http://vger.kernel.org/majordomo-info.html >> >