[Gluster-users] Adding Gluster support for Primary Storage in CloudStack

[Niels de Vos]

On Sun, Dec 01, 2013 at 03:30:55PM +0000, Nux! wrote:
> On 01.12.2013 15:08, Niels de Vos wrote:
> >Hi all,
> >
> >I'd like to inform any CloudStack users that there are now patches [0]
> >available (for CoudStack) that make it possible to use an existing
> >Gluster environment as Primary Storage on CloudStack.
> 
> Hi Niels and thanks for this, it's great news!
> What would be the advantage of using this over the more generic
> "shared mount point", except for doing it more elegantly?
> What everybody is looking forward to I guess is the libgfapi
> implementation that would bypass the FUSE layer and hence boost
> performance.

Currently, users will see little difference compared to using a 
SharedMountPoint. However, CloudStack now knows about storage on Gluster 
and can use that information to build XML files for attaching disks to 
a virtual machine.  If in future the XML is structured correctly, 
QEMU+libgfapi will be used instead of QEMU going through the filesystem 
(fuse-mount in this case). Depending on how much of my spare time I can 
dedicate to this, or contributions done by others, it may happen sooner 
or later...

I do not know if there is a noticeable performance difference when the 
creation of disk-images and their snapshots are done through libgfapi.  
But, anyway, for this to be included in CloudStack, we would first need 
to implement a more complete storage support for Gluster in libvirt 
(based on libgfapi). When libvirt knows how to use libgfapi, CloudStack 
can be modified to move to the new libvirt configuration/usage.

Cheers,
Niels