NetApp's NearStore VTL is based on the FAS 3000 midrange storage array and comes in single-processor and dual-processor models. The array can scale from 4.5TB to 168TB and incorporates file sharing over CIFS, NFS and iSCSI.

The NearStore VTL also comes with a feature called Tape Smart Sizing that NetApp claims can save up to 50 percent capacity on physical tape storage over other vendors' VTLs by predicting how much the data will be compressed once it is transferred to physical tape. The smart sizing feature works by sampling backup data and adjusting each virtual tape to fit the physical tape on which it will be archiving data.

'As you create a virtual tape, the NearStore VTL will know how much raw data to put on it so when it goes to physical tape and it is compressed it will fill the tape completely,' said Krish Padmanabhan, general manager of NetApp's Enterprise Data Management business unit.

Padmanabhan said the NearStore VTL also offers a load balancing feature that can automatically shift backups to disks with higher performance at any point in time. The array also finds the highest performing RAID sets on which to create new virtual tapes and it will move those virtual tapes to that RAID set each time a backup begins.

NetApp gained the VTL software technology from its purchase of Alacritus Software Inc. for $11 million last April. After that purchase, NetApp in June bought data encryption appliance maker Decru Inc.