@DrLogix
Please elaborate on what you mean by back up the datastore, as there are different ways to back up/protect data, two of the common ways are below, however, more clarification will help get the best answer or options for your requirement(s).
- If you're talking about a local datastore on a host, housing VMs, I would use a solution that will back up the VMs themselves to another location. Previous response mentioned RAID, but that will be to accommodate for a failure of one or more disks that make up that datastore, and not technically "back up" the data. To back up the data, you're essentially going to need to create a copy of that data in another location or media.
- If you're using shared storage from SAN, to "backup" or preserve a copy for a certain period of time at the datastore as a whole level, you can use the storage snapshot and replicate feature to first create a snapped copy, then replicate it to another site. You can also do this local to the site, just make sure the storage supports either, and if replicating offsite, it will need to go to similar storage. Keep in mind that this will require additional storage, so keeping copies indefinitely may be a challenge.
Thanks!