Disk 2 Disk backup /VTL

A Virtual Tape Library (VTL) is optimised disk based storage appliance that emulates traditional tape libraries. They logically appear and operate as physical tape devices including virtual tape drives, data cartridges, tape slots, barcode labels and robotic arms and because of this VTL they can be implemented seamlessly and transparently to existing tape backup and recovery solutions.

Traditional tape backup devices have several shortcomings when trying to meet the demands of most of today’s organisations. They are relatively slow and the only way to solve that problem is to add more and more tape drives. Tape library robotics are prone to failure and the tape media itself is "delicate" and must be stored in a conditioned, secure environment. To increase backup performance, backups can be multiplexed across multiple drives and tapes. This increases the odds of a failed backup due to a bad tape, a faulty drive or malfunctioning robotics.

Restores from tape are also time-consuming. Consider trying to recover a file that was part of a five-tape multiplexed backup. Each of the five tapes must be located in the library and loaded into tape drives. If the drives have tapes in them already, the tapes must be removed from the drives and moved to free slots before another tape may be loaded. Once the tapes are loaded, they must be advanced to where the file is and then, finally, the file can be read from tape. It can take many minutes just to start the recovery. If the tapes are not in the library, it can take many hours to recover a single file.

A virtual tape library solution can perform 10-times tape speeds for backups. Speeding up the backups will greatly shrink the backup window, which allows servers to be backed up faster. With existing backups finishing quicker, second- and third-tier servers that have not been backed up in the past may now fit into the backup schedule.