[Gluster-users] Gluster v 3.3 with KVM and High Availability

[Brian Candler]

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.