Virtual TapeServer 6.04.02 Operations and Administration Guide

2 | Introduction
deploy VTS to simplify and streamline traditional tape operations, reduce costs for storage
hardware and tape media, automate backup and restore operations, and increase flexibility in
managing backed-up data.
The virtual environment
The basic building blocks of VTS are vaults, pools, virtual tape drives, and virtual tapes. VTS
can support multiple virtual tape drives that respond to tape commands just as a physical
tape drive would.
Virtual pools are organized into vaults, which correspond to areas of the file system that are
configured according to user needs. Most frequently, vaults include the entire file system,
though defining several vaults is a convenient way to separate data for different applications
or users. As an analogy, think of a vault as a file system.
Virtual tapes are “stored” in pools, which are the equivalent to magazines of cartridges used
in tape drive libraries. A pool can contain as many virtual tapes as necessary for a given
application, which provides a great advantage over cartridge magazines that have physical
limits to the number of cartridges they can contain. A pool is synonymous with a directory on
a file system.
Note The VTS web interface refers to virtual tapes as “cartridges.” Note that these terms
are synonymous in VTS.
Virtual tape drives respond to mount, write, rewind, read, and unload commands from
standard backup management applications. Virtual tape drives require virtual tape media,
and VTS enables you to create an unlimited number of virtual tapes. A virtual tape is the
logical equivalent to a physical tape. However, unlike physical tape media, virtual tapes can
be created in any size because the data is pooled on low-cost disk storage. A virtual tape
contains only the data written to it, with no wasted space. When a virtual tape is no longer
needed, it can be discarded just like a physical tape. A virtual tape is synonymous with a file
in a directory.