Example: You have a windows server machine(on datastore1) that has its page file on a different logical drive which is on a different datastore(datastore2). Follow? The reason this was done is so when you storage vmotion, you will have less to move if the page file is not with the VM folder on the datastore(datastore1). So if we have dozens of server page files on a specfic datastore(datastore2), can this be Deduped?
Secondly, I have some customers separating page files into separate datastores, while some just put page files into the same datastores as vswap. NetApp has learned that most customers don't separate the guest and those that do only consume about 0.5% more storage space per day in snapshots. As I understand it in TR-3749, the default is recommended, and is listed as option with a long with a list of considerations/caveats. The general consensus is to not separate into separate datastores, but if you must, then don't enable deduplication on the volume since the storage effiency return on time and effort may not be enough.