Placeholder BZ for caching improvements we could do to improve virtual machine image store performance.
The below changes are been done: * a gluster volume set <> group virt (which would disable not required xlators) * better re-structuring of write-behind * a way to handle O_DIRECT separately in write-behind and in client protocol. * proper mtime update in distribute translator so the caching based on mtime in application is not invalidated. All other caching is done by guest at the moment.