Re: [Gluster-devel] Qemu glusterfs, exposing complete bricks instead of individual images as shared storage to VM's ?

[Niels de Vos]

On Fri, Nov 29, 2013 at 11:06:33PM +0100, Sander Eikelenboom wrote:
> Hi,
> 
> I'm using glusterfs for quite some time on my server for shared-storage to 
> VM's.
> At the moment this had to go over tcp/ip bridge between host and guests, so
> i was interested in the option to use glusterfs directly with qemu. But it 
> seems it
> only supports to expose individual images files that reside on a glusterfs 
> brick.
> 
> Would it be possible to extend this and make a complete brick available as 
> disk to qemu as shared storage ?
> (so multiple vm's and the host can share this same storage space)

I think what you are looking for is the Block Device xlator. It allows 
you to create a brick based on a LVM/VolumeGroup, and files in the 
Gluster/Volume are mapped to LVM/LogicalVolumes. Connecting to the 
Gluster/Volume (over QEMU+libgfapi or the fuse-mount) will use TCP/IP, 
but you remove the overhead of a filesystem on the brick.

A very complete description has been posted by the developers of the 
bd-xlator who also did the QEMU+libgfapi integration:
- http://raobharata.wordpress.com/2013/11/27/glusterfs-block-device-translator
- http://raobharata.wordpress.com/2012/10/29/qemu-glusterfs-native-integration

Cheers,
Niels