ekisner
I work for Quest software. Thanks for your post. Here are some points about our solution. If you would like to have more conversation, please feel free to email me at Kiran.Ranabhor@quest.com.
Quest licensing for vReplicator is based on source-servers only (physical sockets on ESX hosts being protected by vReplicator). Licensing destination (DR side) servers is not needed.
I get your points about the scratch disk. vReplicator uses scratch disks to store the replicated data before applying the changes to the base image. Most of the industry standard replication products I know do this: EMC RecoverPoint, NetApp SnapMirror (array based), EMC SRDF etc. They all create a snapshot on the DR side (or use logs) to hold the changes while the data is being replicated. Once replication transfer is done, changes are applied in one swoop.
In all these situations, scratch space is managed automatically, but its there. vRanger VA requires manual scratch disk management in this release.
This type of scratch disk use is very useful in replication in WAN environments where network can be a little flakey. Helps in avoiding having to re-silver the entire VM if data transfer fails...
Please let me know if you have any questions or would like to chat.
Thanks
kiran.