What does Virtual Tape Library (VTL) mean?
A virtual tape library (VTL) is a technology for data backup and recovery that uses tape libraries or tape drives along with their existing software for backup.
The virtual tape library system emulates the former magnetic tape devices and data formats, but performs much faster data backups and recovery. It is able to avoid the data streaming problems that often occur with tape drives as a result of their slow data transfer speeds.
Techopedia explains Virtual Tape Library (VTL)
The VTL technology does not include physically removable disk drives, and the drives are always powered and connected to data sources. Therefore, removal to a different physical location for safe disaster recovery and storage is not possible, and the powered disk drives are always susceptible to damage and corruption from electrical power fluctuations or lightening strikes. Thus, they are never physically electrically isolated. Both of these factors are disadvantages compared to magnetic tape.
To address these disadvantages, some systems use a VTL and then back up the second hard drive disk to magnetic tape for disaster recovery protection; this is referred to as a disk-to-disk-to-tape (D2D2T) system.
A large percentage of the products sold in the VTL market are based on technology from FalconStor Software Inc., a disk-based data protection software company.