On Thu, Jul 12, 2012 at 09:01:48AM +0300, Samuli Heinonen wrote: > On 11.07.2012 21:35, Brian Candler wrote: > >On Wed, Jul 11, 2012 at 12:55:50PM -0500, Mark Nipper wrote: > >> Would that be using something like O_DIRECT which FUSE > >>doesn't support at the moment? > > > >Yes. FUSE does support it in recent kernels (3.4), and I tried it. > >Nothing > >happened until I also mounted with -o direct-io-mode=enable; with > >that and > >cache=none, the VM was unable to start up at all. > > This FUSE patch has been backported into RHEL 6.3 and should also > work with latest 6.2 kernels. > > Iirc, it also worked with cache=none without any special mount > options, but unfortunately I don't have possibility to test if > that's true :( When I tested it, it did work with cache=none without any special mount options and a kernel which supports FUSE+O_DIRECT, but the performance was no better than without. With -o direct-io-mode=enable the VM wouldn't start at all.
