[Gluster-users] Performance optimization tips Gluster 3.3? (small files / directory listings)

[Brian Candler]

On Sat, Jun 09, 2012 at 09:53:05AM +0100, Brian Candler wrote:
> So clearly cache='none' (O_DIRECT) makes a big difference when using a
> local filesystem, so I'd very much like to be able to test it with gluster.

Aha, O_DIRECT is in 3.4+:
http://comments.gmane.org/gmane.comp.file-systems.gluster.user/8916
http://lwn.net/Articles/476978/

So I upgraded this box to a mainline 3.4.0 kernel from
http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.4-precise/

After this:

* KVM *does* boot with the cache='none' option :-)
* However performance is pretty much unchanged :-(

ubuntu at lucidtest:~$ dd if=/dev/zero of=/var/tmp/test.zeros5 bs=1024k count=500
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 10.184 s, 51.5 MB/s

(As a reminder: that's KVM talking to a single-brick gluster volume,
FUSE-mounted on the same node.  Other tests showed 248MB/s with KVM guest
talking to the RAID10 array directly, and 350MB/s with the host talking to
the RAID10 array directly)

Regards,

Brian.