“I don’t know what hope a VTL has at this point without deduplication,” said backup expert W. Curtis Preston. “I also can’t imagine what it’s like for a company to begin developing a new dedupe product now, and tape stacking that is not controlled by the backup software (and I doubt this one will be) is simply wrong and evil and should be avoided at all costs.”

Any storage device that stores data on the tape in a way that does not allow the backup software to interact directly with said tape is doing a Bad Thing. This includes, but is not limited to, ACSLS and tape stacking that isn’t controlled by the backup software.

I’m fine with tape stacking, for example, if you use something like the NDMP-direct-to-tape feature of NetBackup to control it. But if the backup software doesn’t know what tape its backups are really on, then you are 100% reliant FOREVER on the device that did the stacking. No thanks — especially if it’s from a company that is trying to survive bankruptcy.