instance memory save and restore

Hi, VMWare vCenter has such feature to snapshot/save instance memory along with disk. Then instance can be reverted to that snapshot later when needed. OpenStack doesn't seem to support it. Any plan to work on that? Actually, I'm looking for the motivation/requirement to for that feature. Typically, we snapshot/backup storage, then restore the storage and restart/reboot the host/instance. Would that be sufficient? I think there will be a chance of inconsistence between memory and storage. That's why we may need to save the state of both memory and storage. Does that make sense? Any opinions is welcome. Thanks! Tony