September 2002

Backing Up A PC

New computers are now shipping with 40 gigabyte hard disks. How do you back up such a large disk? Many computers have a CD burner, but it would take 62 CD-R disks (650 MB each) to copy an entire hard disk.

The traditional backup solution is the tape drive. Unfortunately, there are problems with tape drives. They are expensive: a Seagate Travan 20 GB tape drive has a list price of $585 and a single tape is $50. Travan drives also have a reputation for unreliability, which we have experienced first-hand with several drives in the past few years.

If you really must back up the entire disk, DAT tape drives are a good alternative. Generally the drives cost more than Travan drives, the tapes cost less, and they are more reliable. A DAT drive makes sense for a file server, but it is too expensive for most people to use on a "personal" computer.

What Is A Backup For?

Consider why you need to back up your hard disk. Here are three reasons:

  1. Easy recovery after a hard disk failure.
  2. Recovery of individual files.
  3. Off-site data storage in case of catastrophe.

Tape backup meets all of these needs, although recovery of individual files is usually a very time-consuming process.

The first two items can be accomplished by backup onto a second hard disk. An Iomega 40 GB external disk, which plugs into a USB port, has a list price of $190. It's easy to recover files. However, while they are portable, this is not a convenient way to get off-site storage.

File servers generally need both tape backup and hard disk backup. Tape backup works well for off-site storage, assuming you rotate among several tapes and always keep a recent backup at another location. Built-in RAID disk systems use more than one disk to ensure continued operation if a hard disk fails. The cost involved makes sense for a file server, but not for an individual PC.

CD-RW Backups

For a more economical solution, our advice is to give up the idea of copying the entire hard disk. Accept the fact that after a hard disk crash it will take some time to restore your programs and data, or buy an external hard disk.

A CD-RW drive can store your data. A simple scheme requires backup software that can write to a CD-RW drive and three CD-RW disks. Each Monday night, the backup software writes a complete copy of your data to the CD-RW disk. On each subsequent night, the backup software writes an incremental backup, which only saves files that have changed since the last backup. On Monday morning, you remove the CD-RW disk (to be taken off-site) and replace it with another one.

In order to be used this way, with separate backups written each night to the same CD-RW disk, the software must format the disk and use special techniques. The result is a capacity of approximately 575 MB per disk.

Zip Drives

Iomega recently introduced a 750 MB Zip drive with a list price of $180. A package of three Zip disks costs $40. With capacity comparable to a CD-RW disk, this might be a good alternative.

A Zip drive has the advantage over a CD-RW drive that Windows sees the drive as an ordinary disk. Individual files and folders appear as they would on a floppy disk. It's easy to copy files directly to the Zip drive.

Previous Zip drives, with 100 and 250 MB capacity, were often too small for backup. The 750 MB drive should be large enough for most people. However, the drives are very new and their reliability cannot be assessed yet.

What To Back Up

How do you get all of your data on one disk? The answer is to use the backup software to select only those directories that contain changing data. Don't back up programs, because you can restore them from the original installation CD. Don't back up Windows itself, because you can re-install it from a CD.

Next consider your data and how it changes. If you keep documents for many years, put old documents in a separate directory. Save such directories on a CD-R disk and take the disk off-site. Don't include those directories in the nightly backup to CD-RW or Zip disk.

Be aware that software vendors may mix programs and data in the same directory. Although Microsoft recommends installing programs in Program Files and data in My Documents, not everyone follows that recommendation. Indeed, our very own RTG Bills software stores its programs and data files in the same directory.

Backup Software

If you decide to make nightly backups to CD-RW disks, you need special software to do it. The backup software that Microsoft supplies with Windows (even Windows XP) cannot write directly to a CD-RW disk.

Recently we've been testing Stomp's Backup MyPC on Windows XP. The list price is $79. They offer a free 30-day trial version, so you can check that it is compatible with your hardware - a very important step. This program can create backups on CD-RW drives as well as Zip drives.

Backup MyPC Version 4.81 took 22 minutes to format a CD-RW disk, which then showed a capacity of 576 MB. A full backup of selected data (the Monday backup) required 109 MB, leaving plenty of room for four incremental backups (Tuesday through Friday).

Backup jobs can be scheduled in the software. They appear in the Windows Scheduled Tasks folder. We have two backup jobs: the full backup and the incremental backup.

You can reduce the size of the backup by excluding specific file types. For example, exe files are programs and hlp files are Windows help files. Don't back these up, because they will be re-installed with the programs.

Here's a complete list of the file types we decided to exclude: bak, dll, exe, gid, hlp, lnk, ocx, and pif.

Backup MyPC does have some disadvantages. A CD-RW disk is treated as if it were a tape. Windows shows that it contains a single file. To access the directories and files, you'll need the Backup MyPC software. Also, we've heard that support from Stomp is poor (some say non-existent). Use the trial version to be sure that it works on your system before you buy it, and accept the possibility that if you buy a new CD-RW drive, it may not be supported.


If you work on a network that has a file server, you should be storing your data on the file server so it can be backed up every night. DAT drives are the usual choice for the server backups.

If you don't have a file server, but your PC has a CD-RW drive, consider using CD-RW disks for data backup. Make sure you have CD copies of your software. Copy unchanging data to CD-R disks. Keep these disks off-site. Set your backup software so it only backs up data that changes, so you do not exceed the capacity of one CD-RW disk. Rotate disks and take disks off-site regularly in case of catastrophe.

If a quick recovery after a hard disk failure is important, use an external hard disk to copy the entire contents of your primary hard disk every night. The CD-RW backups are still important, though, to provide off-site storage of your data.

RTG Bills and RTG Timer are trademarks of RTG Data Systems. Other company and product names may be trademarks of the companies with which they are associated.

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