[EDITOR: Below you will find the second self-syndicated SIMSON SAYS column, written by computer journalist Simson Garfinkel. This article is being submitted to you for your newspaper to run on a non-exclusive basis.

Mr. Garfinkel was a computer columnist for The Boston Globe between 1996 and 2000. This summer he is writing the SIMSON SAYS column and sending it out to newspapers around the country.  If you are interested in publishing this column, feel free. Information regarding payment can be found at http://www.simsonsays.com/ or by contacting Simson Garfinkel at (simsong@acm.org). Last week’s Simson Says column was on the subject of SpamAssassin, a powerful anti-spam system.  You can download that column from http://www.simsonsays.com/. ]

SIMSON SAYS:  How to back up 160 gigabytes

Thanks to the tremendous drops in the price of storage that we’ve seen in recent years, you can now purchase a 160 gigabyte hard drive for less than $240. Don’t need so much storage? That’s okay---you can buy an 80 GB drive for just $90!  But if you buy one of these megadrives, you’ll soon be faced with a dilemma: how do you back it up?

Back in the 1990s, many people who bought a PC for a small office would shell out an extra $300 or $500 and buy a tape backup system. Most of the popular tape systems were slow, but they stored about as much information as a typical hard drive, making these tape backup systems a good match for typical desktop computers. They were easy to use, too: Just start the backup system before going home at night; by the next morning the whole disk was backed up.

With tapes typically costing between $20 and $30 per cartridge, these backup systems were cost-effective as well. And as any network administrator would tell you, these tapes worked: when a hard drive failed, as all hard drives eventually do, it was a simple matter to replace the drive and restore the tape backup. Even better, tapes were a safety net for users, protecting them against accidental file deletions or corrupt data.

Like the price of hard disk systems, the price of tape backup has dropped in recent years. Unfortunately, it’s not dropping as fast. Thus, what started out as a mild disparity between spinning storage and tape systems has compounded significantly over the past year. These days, a typical DDS3 tape drive that stores 24 gigabytes on a tape costs roughly $700; tapes are $10 each. An AIT+ drive that stores 70 gigabytes on a tape costs $900; AIT+ tapes are $75 each.  

In sum, tape is no longer a bargain: the cost of storing 70 gigabytes (GB) on a tape is only $15 less than the cost of storing 80 GB on a spinning hard disk --- and that’s before you factor in the price of the tape drive itself! Given these economics, more and more people that I know are doing away with tapes entirely, and keeping their backups on other disks.

Nevertheless, tapes still have a few advantages over hard drives. A 70 GB tape takes up a perhaps a tenth the shelf-space of equivalent hard disk. Perhaps more importantly, it’s a lot easier to pop a tape into a tape drive than to open up a desktop computer and hook up another IDE drive. What’s more, many backup programs work better backing up to a tape than to a disk. As a result, people who do disk-to-disk backup systems often end up devising their own backup “solutions.”

The easiest, cheapest way to protect yourself from a disk failure is simply to buy a second hard disk and copy the files from your computer to the backup drive on a regular basis. I like using backup drives that have FireWire interfaces (also known as IEEE-1394). Most Macs now come with FireWire built-in; if you have a PC, you’ll need to buy a FireWire interface card, which can cost anywhere from $25 and $75. Be advised: these interfaces require Windows 98 Second Edition, Windows ME, or Windows XP to operate properly.

If you have several computers in your house, you can certainly drag the drive around from computer to computer. Alternatively, you can network the systems together and arrange for each the systems to back each other up. Windows, MacOS and Unix can all share disks over the network, so you can easily use one computer’s external drives from another computer’s desktop. If you do machine-to-machine backups, you’ll want to be sure that you have a network that runs at 100 megabits per second. Don’t try backing up over a wireless LAN: it takes too much time. (Wireless also isn’t very secure, but that’s another matter entirely.)

One way to back up your data is to create an empty folder on the external drive with today’s date, then copy over all of the files you want to keep into that folder. If you are running Windows 98, you can back up your system with Microsoft Backup, which will also back up your registry, so you can restore your files as well.  Veritas Software has a similar program called Veritas Backup MyPC that costs $65. When you run either of these programs on a PC that doesn’t have a tape drive, they will complain that they cannot find a suitable backup device; just click “OK” if you get this warning and tell the program that you want to backup your PC to a file that is the external or network drive. Be careful that you only backup the files on your internal hard drive, otherwise you might end up backing up your backup!

Another nice thing about having an external backup drive is that you can transport it around. For example, you can buy two, and keep one at your house and one in a safe deposit box. This will protect you against fire, theft, and other maladies.

If you want more protection then you’ll get from making an occasional copy of your computer’s hard drive, invest in both a second internal hard disk for your system and a RAID controller card. RAID stands for Redundant Array of Independent Disks: these systems run two disk drives together as a single unit, writing all data simultaneously to both drives. When one of the drives fails, the RAID system gives you a warning. Buy a drive to replace the busted one, and the RAID controller copies all of the data on the one remaining good drive onto your new drive.

Two popular RAID cards are from 3Ware and Promise; expect to spend between $60 and $200. Software RAID systems are also built into both Windows XP and MacOS X. While software RAID works okay, hardware RAID is both faster and more reliable. And whatever you do, be sure that you set the system up for RAID Level 1 rather than Level 0. RAID Level 1 is “disk mirroring,” which causes the same data to be written to both drives. In RAID Level 0, the two drives are simply spliced together to form a single drive that’s twice the size. You’ll get more storage space, but you’ll have only half the reliability.

Finally, for the best prices on disk drives --- and a whole lot more --- check out PriceWatch (www.pricewatch.com). PriceWatch doesn’t sell equipment, but it tracks the prices posted on dozens of websites for hard drives, RAM, and many other kinds of commodity hardware.

Simson Garfinkel

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