From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: Problem using exportfs in an active-active nfs cluster Date: Wed, 9 Jun 2010 07:54:25 +1000 Message-ID: <20100609075425.7ec4ccd9@notabene.brown> References: <4C0E6ED0.60200@miamammausalinux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linux-nfs@vger.kernel.org To: rasca-9B074fXSGsOr88ip1nKoZ2D2FQJk+8+b@public.gmane.org Return-path: Received: from cantor.suse.de ([195.135.220.2]:44941 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755406Ab0FHVyc (ORCPT ); Tue, 8 Jun 2010 17:54:32 -0400 In-Reply-To: <4C0E6ED0.60200-9B074fXSGsOr88ip1nKoZ2D2FQJk+8+b@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, 08 Jun 2010 18:24:48 +0200 RaSca wrote: > Hi all, > I'm trying to use a resource agent named exportfs for my active-active > nfs cluster configuration. > The resource agent works using the exportfs command. I have an instance > of nfs-kernel-server for each node and exportfs dynamically remove or > append the export to the node (obviously I've got also a shared storage). > The problem comes when the export is mounted by a client and this client > is writing on it: if the node switches, then the migration fails. The > sequence is this one: > > - The resource exportfs stops correctly (the Resource Agent launch > exportfs -u) > - The Filesystem resource tries to unmount the exported filesystem, > doing an fuser to see if some processes are locking the fs. > - fuser doesn't return anything, but the filesystem is still locked. > This happens because the kernel process nfsd is locking the FS. > - The migration fails. > > The only way to make thing work again is to restart the > nfs-kernel-daemon on the node which the resource reside and then cleanup > the resource. > > Now, after many discussions on the Linux-ha Mailing List, I'm here to > ask if this problem is about the exportfs command. Why a filesystem > remains locked to the nfsd kernel process even if I (or the resource > agent) have done an "exportfs -u" command? > > What can else I do to free the exported filesystem? Note that I've tried > to mount from the client with "nolock" option and also the exported > filesystem is mounted with "noatime". > > Thanks a lot, > Try exportfs -f NeilBrown