The virtual tape library or emulator will be a port of what was StorageTek’s VSM mainframe VTL to Open Systems. It was originally slated to ship in the first half of last year, a date which later slipped to the second half of last year.

We’ve nearly completed porting that software to open systems, Mark Canepa, vice president of Sun’s storage division, said last week. After that is done, Sun will still have development and testing work to do. We should have some prototypes soon, Canepas said, and some products shipping by the end of the year.

As yet more evidence that the product is some way off from shipping, Sun began OEM’ing VTL software from FalconStor last fall, in order to fill the gap in its product portfolio. For obvious reasons, it did not publicize that move.

Sun is the third large supplier that is OEM’ing FalconStor’s eponymous VirtualTape Library software. The other two are EMC Corp and IBM Corp, who began OEMing the FalconStor product in 2004 and 2005, respectively.

IBM is also only using FalconStor as a placeholder, because it too is developing its own in-house Open Systems VTL. Like Sun, IBM already ships a mainframe VTL. One source said that there is already an open systems version of this product that has sold very poorly — if at all.

According to Sun, it and IBM own the mainframe VTL market, with Sun taking around 70% market share, and IBM almost all of the remainder. But translating that dominance to the open systems world is proving to be a challenge to both companies.

In an email to Computer Business Review, IBM said: Simply migrating a mainframe VTL into open systems environments will normally not result in a cost competitive offering, so significant design changes can be required. Also, mainframe VTLs are true tape virtualization devices — they put a layer of virtualization capability over the tape infrastructure — whereas opens systems devices are generally tape emulators — they look like tape to the system.

The IBM statement concluded: There isn’t a single disk subsystem that goes across the entire spectrum of mainframe to open systems. Likewise with tape virtualization.