Lots of questions and tidbits of information that lead me to believe that you would see lots of benefits from many of the other NetApp storage efficiency components beyond deduplication alone. You should probably contact a NetApp sales team to learn more about the other storage efficiency technologies, many of which are included for free.
For now, let me address the most abvious points.
First, some basics. NetApp deduplication is free, and completely native to the NetApp system. This means that NetApp dedupe was designed to work with all the other cool NetApp features. In addition, NetApp is recognized as the industry leading solution for running deduplication on your primary production systems on data that is actively being used, with 30,000+ licenses currently installed. The last basic point I will make is that NetApp deduplication can be used in both a SAN and NAS environment, both of which can be served from a NetApp storage system. Managing both from a single system goes a long way in saving man hours.
A key differentiator for NetApp is that it is a block-based deduplication. The net affect of being able to go below the file level to look for duplicates is that NetApp dedupe has much more opportunity to find duplicates for space savings.
You mentioned server virtualiztion, and that brings me to another NetApp differentiator. NetApp supports deduplication with server virtualization, as well as desktop virtualization (VDI), and we are continuing to grow the features around this environment. We are now able to create virtual servers and desktops in a deduplicated state. Using this approach means that you can now create virtual systems and recognize the space savings immediately. Remember, these are live usable systems, not an archive of a system or a system that is not being actively used.
You also mentioned sharepoint, so I must mention that NetApp dedupe typically sees about 30% savings in live sharepoint environments.
As for the backup scenario, deduplication does not apply to tape at this time, well at least not to a generic tape format. When deduplicated data is written to tape, it is done so at the logical level. This results in a tape that contains files in a generic format that can be easily restored. The downside is that backup and restore windows grow fast, and tape is not keeping up. The popular alternatives are NetApp Snapshots and NetApp SnapVault. Snapshots allow you to take point in time copies of your data, and store them locally for quick restores as needed. Snapshots are extremely efficient becuase they only store the changes since your last snapshot. And to take this effieincy even further, if you take a snapshot of deduplicated data, then the savings provided by deduplication will be maintained within the Snapshot. This compounded savings is very effective and provides great savings. Now SnapVault is the NetApp disk-to-disk backup application. It basically takes the Snapshot technology, and allows you to store the snapshots on a separate system as a backup. Because SnapVault only transfers the changed data, it results in very thin transfers of data from your primary system to your backup storage. And then even more savings can be recognized on the storage system by using deduplication.
Well this was my attempt to address the main points of your posting. There is likely lots of additional storage savings to be recognized in your environment beyond what I noted here. Including all the options for you to consider is way beyond the scope of this post. I will come back to my recommendations for you to learn more about NetApp Storage Efficiency, and to contact your local NetApp account team so they can give you properly qualified information for your specific environment.
Let me know if you need any additional clarification on the points above.
