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Backing up is hard to do

technofile  by al fasoldt

Columns and commentaries in a life-long dance with technology

Simple gray rule

Backing up is hard to do—but you'd better start now

By Al Fasoldt

Copyright © 1995-1996, Al Fasoldt and the Syracuse Newspapers

I get distress calls like this at least once a week:

"Something went wrong with our computer and we can't seem to get it running right. Some of the files are missing. Can you help?''

Sometimes I can help. But I always ask a question first: "Do you have a recent backup of everything on your computer?'' The answer is usually a hemming and hawing followed by an embarrassed silence.

I ask that question because I'm reluctant to suggest any action that would endanger the lost files any further. I don't want to be blamed for turning an emergency into a disaster.

And I always try to avoid lecturing the callers. They're in enough trouble. The best time to review file-backup procedures is when everything is running right—such as now, while you are relaxing with the newspaper.

So listen up if you own a computer that has vital files. It will pay off someday.

Every new computer comes with a built-in storage device called a hard drive. It has disks inside it that spin very fast. Files are stored on this drive the same way they are stored on a floppy disk, except that the hard drive works a lot faster and stores a great deal more files.

Hard disks are set-and-forget devices. When they work, they do their job without fuss. But they do not work forever. If you remember only one thing, let it be this: Every hard drive will fail. The only question is when.

This means that hard drives are temporary storage devices. That puts them in a different class from filing cabinets or desk drawers, which can be expected to hold what you place in them just about forever. All hard drives will stop working at some point.

Unfortunately, hard drives do not send a telegram informing us of their plans to retire; they work fine one day and die the next. Sometimes they can be brought back to life long enough to let an expert pull off the lost files, but just as often as not they take their vital contents to their graves.

What can you do about this? The answer is simple: Always have copies of every important file on your hard drive. Note that I didn't say, "have a copy''—I used the plural for a good reason.

You don't need to make use of backups except in emergencies, which means the only time you'll get out your copies to put the files back onto your hard drive will be the same time you are nervous and likely to make a mistake. And that mistake, more often than not, will be to mess up the only surviving backup copies of your files.

And so you need at least two sets of backups. Many experienced computer users have three, and they rotate them—making fresh backups over the top of the oldest set of copies. The idea is that while they are copying the new backups (and wiping out the oldest ones), they are putting both the originals and one set of backups at risk, so they need those other two sets as a kind of insurance.

All this takes time and is a lot of trouble. Sounds like fun, right? But let me explain something first. The typical hard drive on a new personal computer can hold 500 million to 2,000,000 million bytes of data. These millions of megabytes don't fit easily on floppy disks any more, so the worst kind of backup method is copying to floppies.

Floppy disks in any PC or Macintosh you can buy today hold just under 1 ½ megabytes of data. You'd need more than 100 of them just to back up the contents of a 150-megabyte hard drive. On a computer with a 1.5-gigabyte (1,500 megabyte) drive -- quite common these days -- the number of floppies required rises to about 1,100. Even if you could shuffle floppies in and out of the drive slot at the rate of one every minute, backing up a modern computer's drive would take more than 18 hours of non-stop floppy-in and floppy-out diddling.

There goes the weekend!

Since time is money, the fastest backup method is usually the cheapest. It's also the best, simply because you're more likely to use a method that doesn't take up half your free time.

Three backup options make sense.

The first is a tape backup system. Tape drives don't cost much (as little as $120 for PCs and $400 for Macs) and the tapes themselves are inexpensive, too. You stick a tape cassette into the drive slot and click a few times with your mouse and walk away.

But tape has a disadvantage. If you need files in a hurry, you can't use them in the form they are in on tape. You first have to copy them back to your hard drive. This tends to be a bother, although it shouldn't get in the way most of the time.

The second is the fastest method, and in most cases it's the easiest. All you do is add a second hard drive to your computer the same size as the first one. Every day, every few days or every week you run a program that equalizes the contents of your primary drive and your backup drive. (In other words, in turns your second drive into a mirror image of the first.)

Isn't this dangerous, since hard drives are bound to fail sooner or later? No. The chance that both drives would fail at the same time are too remote to worry about.

The third is the most expensive, but it's the best if cost is not considered. You add an optical disk drive and do all your backups to a removable optical disk. One disk can hold as much as 1,300 megabytes and generally costs $100 or so. This method lets you create sets of backups easily, and the disks are more rugged than magnetic ones.

What you might call option 3B is attractive, too. CD-ROM recorders cost as little as $400 if you shop around, and they'll let you create a CD-ROMs that can be used on any CD-ROM drive. They're ideal for backups.

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