Hardware Reference
In-Depth Information
Externalharddrives
As useful as DVD+R discs and USB flash drives are for routine partial backups,
they have neither the capacity nor the speed for full backups of a system with
a large hard drive or drives. For that, the only practical solution is to back up to
another hard drive.
The mainstream solution is to use external hard drives, which are available from
numerous manufacturers—including drive manufacturers Hitachi, Samsung,
Seagate, Toshiba, and Western Digital, as well as many other vendors—in ca-
pacities from 20 GB to 3 TB. The smallest units use 2.5” 5,400 RPM notebook
hard drives, are powered by the USB cable, and fit in your shirt pocket. The
highest-capacity units use 5,400 or 7,200 RPM desktop hard drives, and are still
small enough to be easily portable.
If you decide to use an external hard drive (or, better, multiple drives) for back-
ing up, pay close attention to the interface(s) it offers. Units are available for
USB 2.0, USB 3.0, FireWire, eSATA, and various combinations thereof. The vast
majority of external hard drives currently in use are connected to USB 2.0
ports, which is fine if you have only a few GB to back up but is much too slow
for doing routine backups of large data sets. If you routinely do backups of 100
GB or more, an eSATA or USB 3.0 model is a much better choice because the
data-transfer rate is limited only by the speed of the hard drives.
Most external hard drives include backup software for Windows. The first time
you use the drive, you simply plug it in, power it up, and allow the software to
install on Windows. The software does a full backup of your Windows system.
(If you're using USB 2.0, this initial backup may well take overnight to finish.)
When the backup completes, you can shut down the drive, disconnect it, and
take it with you when you leave the house. When you reconnect the drive to
your system, it automatically scans for new and changed files and does a quick
differential backup of only those files. Most external drives can be used with
more than one computer to maintain separate backups for each.
Among the many USB 2.0 external drives available, we recommend the
Seagate Free Agent
series (
http://www.seagate.com
)
. They're available in ca-
pacities from 240 GB to 3 TB, and the bundled software is excellent. If you have
a USB 3.0 port available and need a fast, high-capacity external drive, choose
one of the
Western Digital My Book
models (
http://www.wdc.com
)
.
But, before you buy an external drive, read on.
Removableharddrivebays
External hard drives are convenient, but the problem is that you really need
at least two or three of them to maintain an adequate set of backups. Each
time you buy an external hard drive, you're paying for the external enclosure
and the backup software. If you can get along with only two or three external
drives, that cost premium is not outrageous. But if you need more, the cost
starts to mount up. (Robert, for example, routinely uses more than a dozen
external drives, both for backups and for archiving data off our disk arrays and
into deep storage.)
