Maxxan, StorageTek, EMC, IBM, Falconstor, Tandberg, Sepaton - the roll of suppliers with virtual tape products (VTL) has been growing steadily. ADIC and Overland have systems too. But not Network Appliance. Now, on Monday, 6 February, it will have.

NetApp's VTL is based on its NearStore nearline storage arrays using inexpensive ATA drives. The software comes via its acquisition of Alacritus in April, 2005.

The VTL600 has one controller and scales from 4.5TB to 84TB in capacity. Its write through speed is 1.8TB/hour. The two-controller VTL1200 can hold up to 168TB of data and its write through speed is 3.6TB/hour.

It can be subdivided into 256 virtual libraries. The VTL600 supports up to 128 virtual libraries, 1,024 tape drives and 8,192 slots. These are capacious devices.

Virtual tape products store data on disk files that appear to be tape drives or libraries. This takes far less time than actually writing the data to a slow tape cartridge and also provides much faster file restoration; at online disk file access and read speed instead of tape cartridge mount, file access and read speed.

Virtually all tape library vendors and most disk storage infrastructure vendors have already announced such products. Data is written to tape after it is backed up on to disk providing a two level backup system with older data on tape and newer backup data stored on disk. Most file restorations are needed from newer backups.

The NetApp VTL appliances work with all leading backup vendors' software: Bakbone; CA; CommVault; EMC Legato; Symantec (Veritas); and Tivoli. They can emulate tape libraries from ADIC, HP, IBM, Quantum and Sun's Data Management Group - the acquired StorageTek.

Acknowledging its products are late to market NetApp spokespeople said that its VTLs had advantages others did not have:-

1. There is an automated tuning feature for the rebalancing of backup streams as the overall backup load changes.
2. An incoming backup data set is scanned so that disk space is properly allocated and not over- or under-allocated. Its compressed size is predicted to more accurately assign disk space to it.

The VTL market leaders are Sepaton ('no tapes' when read backwards) and FalconStor. There is no reason to suppose that NetAp's own customers will be anything other than delighted with the new appliances. However, in a now crowded market it remains to be seen if NetApp channel partners can sell these VTL boxes into non-NetApp customers against competing products.

New Decru appliance
NetApp is also going to announce a new encrypting appliance from its Decru unit. The DataFort E-Series version 3.0 combines the encryption of network-attached storage (NAS) and iSCSI. Previously two separate products were required. Now storage data travelling over Ethernet to storage devices can be encrypted for safer transport and storage.