Backing up of a computer's files is something that should be done on a regular basis. Unfortunately, not very many of us do this. Any experienced user would backup their files, right? That isn't necessarily true. I have two usb portable drives on my system as well as one firewire drive. I am embarrassed to say my backup is at least six months old and a fresh backup is long overdue.

External USB drives are an excellent media for backing up due to the portability of the drive. For example, if you have a hard drive crash, a backup would be essential to a recovery of your files. With a restore from backup, you would only lose items that had changed since the last backup. Software exists at a very reasonable price that only backs up the files that have changed since last backup. With this, one could backup every night or 3 times a week, or any frequency you choose.

If you buy a new computer, using your backup, you could move all of your files such as photos, spreadsheet, Quicken financial data, etc from the backup to the new system for a painless changeover. In addition, you could simply unplug your drive and take it to grandma's with you and show your photos to all of your family.

There are several types of backup strategies you might employ using USB Portable Drives. One of them is the RAID configuration of your hard drives. RAID is an acronym for Redundant Array of Independent (or Inexpensive) Disks. Definitions of the different RAID levels are:Level 0 -- Striped Disk Array without Fault Tolerance: Provides data striping (spreading out blocks of each file across multiple disk drives) but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost. In the Western Digital MyBook Mirror example, configuring as RAID 0 gives you a larger virtual drive but no redundancy. For redundancy, you would use RAID 1. Your backup space in RAID 1 would be smaller since 1 drive would contain a mirror of the other.
Level 1 -- Mirroring and Duplexing: Provides disk mirroring. Level 1 provides twice the read transaction rate of single disks and the same write transaction rate as single disks.
Level 2 -- Error-Correcting Coding: Not a typical implementation and rarely used, Level 2 stripes data at the bit level rather than the block level.
Level 3 -- Bit-Interleaved Parity: Provides byte-level striping with a dedicated parity disk. Level 3, which cannot service simultaneous multiple requests, also is rarely used.
Level 4 -- Dedicated Parity Drive: A commonly used implementation of RAID, Level 4 provides block-level striping (like Level 0) with a parity disk. If a data disk fails, the parity data is used to create a replacement disk. A disadvantage to Level 4 is that the parity disk can create write bottlenecks.
Level 5 -- Block Interleaved Distributed Parity: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID.Level 6 -- Independent Data Disks with Double Parity: Provides block-level striping with parity data distributed across all disks.

Most home users would select either RAID 0 or RAID 1. The other levels would primarily be server side configurations.

Since I am one of those that occasionally forgets to backup as frequently as I should, I am looking to get one of the Western Digital MyBook Home external usb drives and relieve myself of the necessity of remembering.