Just Do Backups

1. I'm too busy to do backups at home. I can rebuild the computer, right?

1. I’m too busy to do backups at home. I can rebuild the computer, right?

Backups are an often-neglected task, even by experienced system managers. Yes, they’re a hassle. Yes, they’re time consuming. Even so, backups are vital!

All too often, people think you can simply rebuild a system if you lose a disk. That’s true, to a point: hardware is cheap and readily replaced; you can reinstall the operating system and third-party applications easily; and while rebuilding and reinstalling system configuration files can be time consuming, even that isn’t difficult.

So why backup at all? The real danger of skipping backups lies in the uncountable (and probably invaluable) files, email, data, and programs that you’ve accumulated on your system. Rebuilding all that is simply impossible. You backup data because losing data, even a little, can make your life very unhappy. (In fact, some studies claim that the value of 100 MB of corporate data is worth $1 million. With disks at 100 GB — that represents $1 billion dollars — and growing… well, do you really need more convincing?)

So, what are your best options for backups? You can use some form of tape or other removable media, or you can use RAID or disk backups.

Removable media is the mainstay of backups in the IT world, almost since tape and disks became part of the computer. But how do you capture the contents of 100 GB disk drives? Here are some choices:

  • Zip disks. Iomega has a decent solution with 250 MB on a disk. Zip disks are an excellent choice for moving or protecting larger sets of data, and are a very good solution for incremental backups even from 100 GB disks.

  • Tape. Magnetic tape is still a solid solution if you can get the right size drive and tapes for your backup needs. However, for the home user, the hardware expense is probably prohibitive.

  • CD. At less than $1 per disk for CD-R media, and CD-RW only slightly more, compact discs are a cost-effective media. CDs are good solution for backups in the <3 GB range, and are good for protecting or moving large data sets.The disadvantage of CD media is speed. CDs tend to be slower and more temperamental.

  • DVD. At 4.7 GB, DVD offers some possibilities, but it’s a fairly new option and may be too expensive for many people.

The sidebar “Media Sizes” lists some sample media sizes available from Sony. The list is not exhaustive, and there are many other vendors and types and sizes of media to choose from.

While the backup strategies for RAID and disk backups are slightly different, the costs for each solution are comparable. With 120 GB disks running less then $200, it’s cost effective to put a second drive in your system and backup to it. Better yet, if you have multiple machines, you can put that drive on a different system and backup to there.

RAID is a good option to recover from disk failure, but keep in mind that RAID can’t recover deleted or corrupted files.

The best recommendation? For a small office or home office (the so-called SOHO environment), keeping costs down are the key. Given that most systems have a floppy drive and, frequently, CD-R, use those devices as a foundation.

Use the floppy drive to handle moving small files and making fast, small backups of key items. Use CD-R/RW to backup smaller file systems or to handle incremental changes. If you use a CD for backups from the time the system is new, you’ll be able to keep up with new data as it comes in to the system (but recovery may be slow as you’ll have a large number of incremental backups to restore).

Cap the whole solution with a second disk for full backups. Ideally, this second disk is in an ejectable case that allows you to remove the drive when backups are completed.

Weigh your options and tolerance for data loss. Choose a strategy that is a reasonable compromise between your budget and tolerance. But most importantly, just do backups.

Sample Media Sizes

Floppy: 1.4MB

CD-RW: 650MB

DVD: 4.7GB

Sony DDS:

60m 1.3 GB (2.6 GB w/ compression)

120m 4.0 GB (8.0 GB w/ compression)

150m 20.0GB (40.0 GB w/ compression)

Exabyte EXB-8200: 15m 0.3GB, 112m 2.5GB

Exabyte EXB-8700: 15m 1.2GB, 112m 10GB

John R. S. Mascio is a systems and network manager. He can be reached at mascio@ryu.com.

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