On Thu, 05 May 2016 20:54:31 -0000 Server Angels <ad...@serverangels.co.uk> 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" <aneesh.ku...@linux.vnet.ibm.com> (supporter:virtio-9p) Greg Kurz <gk...@linux.vnet.ibm.com> (supporter:virtio-9p) I'm now catching up on the background for this issue. Cheers. -- Greg