A Virtual Tape Library (VTL) is an emulation of a physical tape library on a disk-based deduplication and compression system such as the DR Series system. The tape library is exposed to a Data Management Application (DMA) as if it is a physical library with tape drives and cartridges, which the application uses for backup. Because a VTL completely emulates a standard library, the introduction of virtual tape is seamless and transparent to existing tape backup/recovery applications. The management of the library, including the drives and tapes, is done by the DMA using SCSI commands. For details on the applications supported, see the DR Series System Interoperability Guide.
This topic introduces and briefly defines some basic VTL terminology used throughout the DR Series system documentation.
||A library is an emulation of a physical tape library and shares the same characteristics such as media changer, tape drives, and slots (cartridge slots).|
||A Tape drive is a logical unit which is part of the emulated library. The media or cartridge is loaded in the Tape drives to be accessed by the Data Management application.|
||Tapes are represented as files and are units within the VTL where data is actually written. Tapes are loaded into a Tape Drive before being accessed.|
||Tapes are parked in Slots before they are retrieved by the data management application for access.|
The DR Series system supports the following virtual tape library (VTL) tape access protocols.
- Network Data Management Protocol (NDMP)
- Internet Small Computer System Interface (iSCSI)
- Fibre Channel (FC)
The Network Data Management protocol (NDMP) is used to control data backup and recovery between primary and secondary storage in a network environment. For example, a NAS server (Filer) can talk to a tape drive for the purposes of a backup.
You can use the protocol with a centralized data management application (DMA) to back up data on file servers running on different platforms to tape drives or tape libraries located elsewhere within the network. The protocol separates the data path from the control path and minimizes demands on network resources. With NDMP, a network file server can communicate directly to a network-attached tape drive or virtual tape library (VTL) for backup or recovery.
The DR Series system VTL container type is designed to work seamlessly with the NDMP protocol.