StorageTek is planning a mid-range tape library based on its StreamLine technology.

The flagship SL8500 supports 9840 and 9940 tapes (StorageTek's own formats) plus (S)DLT (DEC/Quantum) and LTO (HP/IBM/Seagate), but the company says there are no plans to support Sony's SAIT.

However, the library is not partitioned according to the different tape formats. Instead, it's done on a slot-by-slot basis with the robot "knowing" which format cartridge it is going to pick up and transfer to a drive. Todd Rief, StorageTek director of operational strategy, explained: "With the 9840/9940 it just picks up the cartridge and slams it into the drive; the tape is that robust. It handles LTO cartridges more gently. We've tailored the robotics for different formats."

A SATA disk cache or buffer, known as Indigo currently, will be likely integrated with it, offering virtual tape drives on disk. This will speed up backup times dramatically as they'll take place at disk speeds rather than tape speeds.

The mid-range StreamLine will also support StorageTek's next generation tape format. Rief and Scully confirmed a two-generation roadmap with the first version - we'll call it NGN1 - starting at 500GB native capacity. It will be faster and hold more than the LTO3 format.

NGN2 will be a terabyte cartridge. Thinking about tape developments in general and noting that tape generations tend to double capacity and data speed, it's possible we are looking at a 1Gbit/s transfer rate and 4 to 5TB native capacity around 2010.

StorageTek is convinced that tape will remain the archive medium, citing floorspace and cost grounds. Steven Scully, StorageTek global manager for industry relations asks rhetorically: "With hundreds of terabytes of compliance data a year would you really want to hold that on disk?"

He says StorageTek checked out an optical disk configuration to match the mid-range StreamLine capacity and it required three times as much floorspace and the media cost more than tape.