Why I can't create iSCSI and FC export domains in RHEV 3.0?

Red Hat is deprecating export domain on block devices for several reasons:

1. It cannot be shared from multiple DC's/RHEV-Manager, requiring to detach/attach per import and export operations (that's true for NFS domain as well today, but the plan is to solve that).

2.  The intention is to change the export and ISO domain to become simple NFS mount points, rather than "storage domains". This will allow much easier management / manipulation of VMs / ISOs, managing them in hierarchies, uploading/downloading them externally to RHEV-Manager, etc. This is obviously not possible for block storage.

Since it's planned for the next major version, Red Hat starts to deprecate the block export domain in 3.0. It is still supported in upgrade from 2.2, and possible to create it from the REST API. However upgrade to 4.0 will not be possible if block export domain is defined in the system