Using External Hard Drives to Back Up Your Computer

External attached storage drives have become very popular backup devices in recent years due to their low cost and convenience. But hearken unto me and heed the Backup Nut's warnings before relying on an external hard drive as your sole backup solution. Because as with all backup strategies, using an external drive has both advantages and disadvantages.

Advantages of External Drives for Backup

The main advantages of external storage drives are relatively low cost and convenience of setup. Most external drives support either USB or Firewire connectivity (or both), and installation consists simply of plugging them in to the computer. They're recognized as Plug-N-Play devices on all versions of Windows from Windows 2000 on, as well as all recent Linux distributions and MAC-OS versions.

External drives offer truly astounding storage capacity, limited only by the capacity of the hard drive(s) they contain. Some enclosures support various methods of spanning multiple drives, providing storage capacity in excess of a terabyte.

Some external drives support Ethernet connectivity and can be accessed by any computer that has TCP/IP networking capabilities (which means basically all of them). These drives are commonly referred to as NAS, or "Network Attached Storage" devices. Most of them require some configuration, which usually consists of assigning the IP address, subnet, and gateway information. Others do this automatically if DHCP enabled on the network. NAS devices are especially well suited for use as backup media for multiple computers on the same network, as long as the drives they contain have sufficient capacity.

Finally, external storage drives have the ability to be disconnected or turned off when a backup is not in progress, which helps prevent them from being infected by viruses, spyware, and other malware.

Disadvantages of External Hard Drives as Backup Media

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There are three main disadvantages to external hard drives as backup media. Firstly, full-sized external hard drives are bulky, which discourages users from storing them away from the computer they're backing up. This means that the external drive could be lost along with the computer in the event of fire, flood, or theft.

Secondly, external hard drives are just as prone to failure as internal hard drives, and can be wiped out by electrical surges, lightning, certain hardware failures on the host PC (such as a flaky chipset), or normal wear and tear. Using a RAIDed enclosure reduces, but does not eliminate some of these risks.

Finally, as with any external or removable storage solution, external hard drives do present security considerations. Although users are often too lazy to disconnect external drives and store them elsewhere, a thief could very easily steal an external hard drive and use it to harvest confidential data from it if it's not encrypted and password protected.

How to Back Up to an External Hard Drive

There are a multitude of ways to use external storage devices as backup media. Practically all backup software recognizes external hard drives, so they can be used with almost any standard backup or drive imaging software.

Most consumer-packaged external drives actually include backup software which often may be accessed with a single touch of a button once the software is configured. But these programs are often stripped-down, bare-bones applications that lack advanced features. A more advanced backup application such as the Acronis® Backup & Recovery 10 Family of products is well worth the investment.

Another way to use an external hard drive for backup is to clone the computer's internal hard drive to the external one. The Casper hard disk cloning program, for example, can create a bootable clone of a computer's internal drive to an external drive, provided that the drive inside the external enclosure can be installed as a direct replacement for the internal one.

In other words, if the drive inside the computer is a desktop drive with a SATA interface and a 100 GB capacity, the drive in the enclosure must also be a desktop drive with a SATA interface, and preferably should have at least a 100 GB capacity.

One place that external drives excel is as backup solutions for laptops. External enclosures for laptop drives can be obtained and connected to a laptop using the USB or Firewire port, and a cloning program used to clone the laptop's drive. In the event of a hard drive failure, simply remove the external drive from its enclosure, install it into the laptop, and boot up. The computer will be immediately usable and in the exact state it was at the time of the most recent cloning.