I'm looking at using GlusterFS as the underlying clustered filesystem for a set of (KVM based) virtual machines My initial thoughts were to get the Host server to client-side mirror between two GlusterFS bricks (one of which would probably be local), create the virtual machine's boot disk as a file on the GlusterFS filesystem and then provide that to the virtual machine as a loopback block device. A few questions spring to mind: - Would the replication work as we expect, ie blocks are written to two locations? - Can you loopback mount files as block devices within virtual machines on GlusterFs? - How would the file resynchronise if one half of the mirror went offline for a period of time? My understanding is that Gluster resyncs when a file is opened. Obviously with a virtual disk drive the file is only going to be opened and closed when the virtual machine reboots. If anybody has any experience of issues with running virtual machines over GlusterFS I'd love to hear from them. -- Neil Wilson
