Fast forward to the present, and it's easy to see that the "new" NetApp has moved away from that isolation by extending its line of products and the reach of those products -- for example, the company opened its OS to virtualization.

As a result, NetApp's large applications portfolio will now work on other vendors' storage platforms, which is obviously good news for its existing customers and certainly removes a deterrent to acquiring new customers.

The NearStore VTL is another example of NetApp's enlarged horizon. Interestingly, it's the first appliance that doesn't run the Data Ontap OS common to all other NetApp products; instead, the NearStore VTL appliances run a Linux-based OS.

NetApp's interest in VTL may be rooted in that data-protection confusion I mentioned before. According to Krish Padmanabhan, EMC's general manager of heterogeneous data protection, there are no analyst reports that size up this backup market -- and that lack of numbers probably explains why vendors have discordant views on the importance of VTL.

"We estimate [the market] is around US$500 million" adds Padmanabhan, explaining that according to a user study conducted last fall by TheInfoPro, VTL came up as the hottest storage technology, ahead of such as stalwarts as asynchronous WAN replication, 4Gbps Fibre Channel, IP for SAN, and Serial ATA drives.