Why the export domain type is NFS only?

Latest response

I see that it is possible to attach only NFS export domain to storage pool. But it takes far too long to copy VM or template data to such storage.

 

There is the corresponding note in a documentation:

"Support for export storage domains backed by storage on anything other than NFS is being deprecated. Existing export storage domains imported from Red Hat Enterprise Virtualization 2.2 environments remain supported. New export storage domains must be created on NFS storage."

 

And I am insteresting, that is the reason of such restriction?

Responses

 

RHEV supports two storage types - file and block. File storage, available via NFS, is naturally easier to manage but that comes at the cost of performance. Block is much harder, especially when you want a mobile storage domain, that can be easily attached, detached, copied and moved around. Just imagine trying to handle an LVM structure with several hundreds of LVs and multiple different LUNs attached as PVs, as a mobile storage platform that is supposed to be easily detached and attached to different setups.
 
import/export is not something that is supposed to be happening in a daily routine, so the choice between ease of management and performance is an easy one here.