| Tape backup solutions have been around for
more than three decades. Tape technology continues to improve but you may prefer the quick
speed and random access capabilities offered by other new backup methods.
Some seasoned Information Technology (IT) managers are
getting accustomed to these new technologies and each day getting the courage to step away
from the traditional tape backup model. Let's take a look at some of the solutions
available that are changing the face of backups.
The external
hard drive is becoming popular as an alternative backup device to tape mostly because
of speed, convenience, compactness, and reliability. Think about what you get with
external hard drive. You get a single unit that you can carry with you that plugs right
into a USB port. It can store extremely large capacities like 300 gigabytes (300 GB). Some
recent additions can store 1 Terabyte. And, you have no media to change.
The absence of the need to change media is probably one of
the most important advantages of using disk methods for backups over tape. Tape backup
capacity is limited. For example with DDS technology for tapes, one can store anywhere
from 2.6 to 40 GB compressed on one tape. On the new tape technology known as Exabyte
VXA-X, capacities of 160 GB compressed can be achieved. And, VXA-2 has some benchmarks
like 43 GB per hour in tape transfer speed in the firewire
backup tape drives.
But what if the amount of data getting transferred to tape
in a tape backup exceeds the capacity of the media cartridge? Then, you have to mount a
new tape. On some of the higher-end enterprise servers, it is not uncommon to have to
backup more than 43 GB in a day. And because backups are usually accomplished when
databases are closed for updating (at night) you would have to have a person there to
mount a new tape.
External hard drive disk backups offer the ability to have
truly unattended backups as long as they have the capacity to hold the data transferred
from the input source.
Some enterprises have purchased what are known as tape
libraries or "jukeboxes" that have tape changing arms and store multiple
cartridges. These tend to be expensive and not all backup software can talk to them for
tape changing commands.
There are also Linux
disk copy utilities for those non-Windows and Mac machines that provide a way to copy
a disk partition to another disk quickly.
For example, the Linux "dd" command which has
been around pretty much since Unix came to pass is a direct byte dump of an input disk
partition to another disk or tape. The "dd" stands for data dump. The problem
with dd when it comes to tape backups is that it will not span multiple tapes. Yet if you
are backing up one disk to another disk of the same size and footprint, dd works
beautifully and it is perfect for cloning exact copies of disks. In other words, if you
lose a disk drive, all you have to do is replace it and dd can be used to bring back the
exact image of the last backup. |
