From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37915) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5XLl-0006kv-N7 for qemu-devel@nongnu.org; Wed, 25 May 2016 07:51:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b5XLj-0007Q1-HY for qemu-devel@nongnu.org; Wed, 25 May 2016 07:51:44 -0400 Received: from mail-wm0-x241.google.com ([2a00:1450:400c:c09::241]:35927) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5XLj-0007Ps-5g for qemu-devel@nongnu.org; Wed, 25 May 2016 07:51:43 -0400 Received: by mail-wm0-x241.google.com with SMTP id q62so14585207wmg.3 for ; Wed, 25 May 2016 04:51:42 -0700 (PDT) MIME-Version: 1.0 References: <20140702135258.23882.15100.malonedeb@soybean.canonical.com> <20160505205431.5288.83480.malone@chaenomeles.canonical.com> <20160525131419.287982e8@bahia.lab.toulouse-stg.fr.ibm.com> In-Reply-To: <20160525131419.287982e8@bahia.lab.toulouse-stg.fr.ibm.com> From: Sean Keeney Date: Wed, 25 May 2016 11:51:31 +0000 Message-ID: Content-Type: text/plain; charset=UTF-8 Subject: Re: [Qemu-devel] [Bug 1336794] Re: 9pfs does not honor open file handles on unlinked files List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Greg Kurz , Server Angels Cc: qemu-devel@nongnu.org, "Aneesh Kumar K.V" Apologies - I made the mistake of thinking Ubuntu launchpad was actually functional, as it is I think they simply throw messages on there back to the original mailing list! On Wed, 25 May 2016 at 12:14 Greg Kurz wrote: > On Thu, 05 May 2016 20:54:31 -0000 > Server Angels wrote: > > I would appreciate this patch being committed as I *think* it's > > affecting a system i'm building now. > > > > I have a backup host with 2 VMs. For business reasons they need to be > > network isolated from each other and the host, so each is passed through > > a physical NIC. Each VM does need access to a variable size datastore on > > the host so I am using virtfs /9p to expose a mountpoint to each VM. > > > > The VMs each backup servers to their respective mountpoint to this > > virtfs mount using rsync. Just backing up one server with ~4000 files > > and 3 large sparse VM images saw the open files on the backup host > > increase to over *800000* and the rsync progressively get slower. > > Shutting down these VMs then takes hours as it can't unlock the files it > > has open on the backup host. > > > > I understand rsync does use open-unlink-fstat extensively, hence why I > > think this is the issue. > > > > This is a deal breaker for any production use of virtfs. Does anybody > > know if this is fixed in other builds of qemu? > > > > tl;dr - to recreate this on 16.04 - create a VM with a virtfs/9p mount > > to the host. Do lots of rsyncs to this mount within the VM, watch 'lsof > > | wc -l' go higher and higher on the host. > > > > Thanks, > > > > /Sean > > > > Hi Sean ! > > I've just stumbled upon this mail... maybe worth to post directly to > qemu-devel and Cc: 9p maintainers next time :) > > "Aneesh Kumar K.V" (supporter:virtio-9p) > Greg Kurz (supporter:virtio-9p) > > I'm now catching up on the background for this issue. > > Cheers. > > -- > Greg > >