How to buy a backup tape
library - Tape Library 101
Learn what you need to know when buying your first tape
library for your small- to medium-sized business (SMB) data storage environment,
including when to consider a tape library, the cost of libraries, which tape
format best fits your storage needs, and the differences between tape libraries
A tape library autoloader is a big step up from a tape drive
when it comes to data backup. Backup tape autoloaders offer automatic tape
swapping and generally higher reliability than a standalone tape drive. However,
backup tape autoloaders have a limited capacity and throughput. If you have more
than a few terabytes of storage, you should probably consider a backup tape
library, the next step up.
Backup tape libraries have bigger capacities than tape
drives, but they also have other advantages. "A tape library has more features
[than an autoloader]," said Peri Grover, director of product marketing at
Overland Storage Inc.,
a maker of both
tape libraries. She said a tape library
works when you have "more data and you need to get at it faster, manage it
remotely or split it into virtual libraries."
Generally speaking, a tape autoloader has a single tape drive
and a robotic arm and can handle between four and 24 tapes. A tape library has
two or more drives and robotic arms and can handle from 20 or so tapes up to
Cost for a tape library typically starts at around $5,000 but
can run up to more than a million dollars for a very large unit.
Backup tape autoloaders vs. backup tape libraries
The difference between tape autoloaders and tape
libraries is more than just the number of drives. Tape libraries are generally
much more robustly built and reliable than autoloaders, and even the inexpensive
ones, with built in bar code readers to help organize the tapes. Some libraries,
such as the
Qualstar Rackmount RLS-series,
have components such as servo motors and precision lead screws in their robotic
arms to more precisely and reliably position tapes.
High-end tape autoloaders slightly overlap in capacity
and price with the least expensive libraries. The
Quantum SuperLoader 3
can handle up to 24 TB of uncompressed data using
LTO-5 tapes and
compression. The list price for the Quantum SuperLoader 3 is $5000.
Make sure you shop around when looking for a tape library
because many libraries can take several different kinds of drives. For example,
the Qualstar Rackmount RLS-series can take either LTO-4 or AIT drives.
Most tape libraries, even the inexpensive ones, now offer
encryption. Encryption is especially important when you have to take tapes
off site because it protects you in the event of a lost or stolen tape.
In addition to encryption, many libraries offer write once,
read many (WORM) capability for increased data security and compliance.
Earlier generations of tape drives are popular in bottom end
tape libraries because of their lower cost. But be careful with these.
Although an older generation ape library is cheaper, consider first how much you
expect your data storage news to grow. The older drives have less capacity than
the newer ones, so after a few years, you may find yourself buying additional
older drives for your storage needs.
In tape libraries today, LTO-4 is currently the most
popular format. However,
LTO-5 is just
beginning to arrive and will become increasingly popular as more manufacturers
start to offer it. The market for low-end tape libraries is highly competitive,
so it pays to shop around.
What to look for when shopping for a backup tape
When shopping for a backup tape library, it's important to
anticipate your growth in data storage requirements. Fortunately, all but the
most bare-bones libraries can be expanded by adding more tape slots and
additional drives and robots. Many tape libraries can be expanded simply by
adding cartridge slots, or in some cases, by having the vendor throw a software
switch. For greater expandability you can add additional drives and robots in
modules with more slots.
In addition to cost, the other main disadvantage to a
tape library is complexity. "It's a significantly more complex environment,"
Grover said. Unlike autoloaders, libraries have to be managed by the system's
backup software, and the ability to do things like split a library into multiple
virtual libraries require more sophisticated management.