In Brief

A Stitch in Time

Computer files are the very lifeblood of most organizations. There is absolutely nothing more devastating at every level than the loss of those files. The time and effort needed to restore data can be enormous and life-threatening to most enterprises. Ted Needleman, former editor-in-chief of Accounting Technology, knows the full scoop and the technology available to assist in making backup the routine it needs to be. Here is the latest on the devices that can get the job done.

What Is Backup?

Backup is a generic term for a number of different approaches to the same process: providing alternate copies of important records so that in the event the original records are destroyed, there is enough information to recreate these records to a point that allows the business to continue operations. Rather than a specific process, backup is actually a philosophy about safeguarding information, which should pervade the entire business. While backup usually concentrates on information stored in electronic form, an overall backup plan should also incorporate some methods for protecting records in hardcopy form, such as articles of incorporation, corporate minutes, and similar certificates and papers.

Backup Basics

Backing up a computer is a matter of copying files and programs to a removable media that can be stored away from the system where the information normally resides. While a backup copy ensures that data can be recovered if the computer's hard disk fails, backing up data also serves to protect the information against other potential disasters. This includes fire, flood, theft, earthquakes, and the like. If the backup copy of the data is right next to the original system, there is a strong likelihood that the backup copy will perish along with the original.

Backup copies should be rotated between different storage facilities to minimize risk. For example, one night the backup copy should go in the office safe, the next day it might go into the bank safe deposit vault, and the third day it might be taken home by an employee. Backup copies should be stored in a fireproof safe. Small safes are available in any office supply store or home furnishings store for around $100, and they provide a large measure of protection in case of a fire.

Several books have been written on backup protocol; but for most users, it's pretty simple. First, decide which critical information changes from day to day. This determines which backup procedures to implement. It doesn't mean that there won't be a need to back up every day, but a lengthy daily backup may not be necessary.

There are two primary kinds of backups: complete and incremental. A complete backup entails copying every byte of information on a hard disk, including the operating system and application programs. It is important to keep in mind that the more information that is backed up, the longer the process takes and the more backup media required.

While a complete backup should be performed at least occasionally, most users also perform incremental backups. With this technique, only those files that have been modified since the last backup are archived. The software that comes with most backup devices can recognize the status of a file automatically so users need not keep track of which files have changed.

Incremental backup is the more time-efficient method. But when restoring files, several days worth of backup tapes or discs may need to be resurrected. Keeping track of all the pieces can become a hassle. That's why it makes sense to do a complete backup every few days if possible. Most backup software programs let the user schedule the backup process for a time when the system is not in use, such as overnight.

Another approach is to back up only information that will be difficult to recreate. For example, if original tax prep software program disks or CD-ROMs are already backed up in several locations, it may not make sense to reduplicate the effort. This approach emphasizes backing up just the client files. In the event of a problem with the system, all that is required is to reinstall the application from the original (or backup) media and then restore the data files from the backup media. This approach is particularly efficient when there is a modest amount of actual data files and writeable or rewriteable CDs are used for backup. Backing up specific subdirectories, rather then entire hard disks, is another timesaving approach that works for many users.

Backup Technologies

Years ago, when you talked backup, you were talking about tape drives. Tape is still the most prevalent method for backing up PCs; however, a number of other media, such as writeable and rewriteable CDs, have emerged as viable alternatives.

Having said that, however, tape drives are still the most popular backup devices for important files. The reasons for that popularity are obvious: Tape is a proven technology that has kept pace with increasing hard disk size. Each successive generation of tape drive has offered larger capacity, better speed, and greater reliability. Unless subjected to powerful magnetic fields or intense heat, today's tape cartridges are almost indestructible.

Many of the latest drives are external devices, which plug into the parallel printer port and can easily be moved from PC to PC to back up an entire office. The industry is into the third generation of tape cartridge formats. The original 3M-style cartridges were almost the size of a paperback book. These were replaced by the QIC and QIC-Wide cartridges, which used quarter-inch magnetic tape. The QIC-style cartridge has evolved into the Travan cartridge, which can store up to 10 Gigabytes (GB) of compressed data.

Backup software has improved a great deal as well. With current backup software working with the latest drives, a complete or incremental backup can easily be performed with a single mouse click. Or better yet, the software can be set up to perform the backup unattended, when the system is not being used, such as overnight or on the weekend.

According to a recent report by the research firm IDC, Hewlett Packard's Colorado Memory Systems and Iomega's Ditto drives make up more than 70% of the market for Travan backup devices. Both vendors have models offering up to 8GB or more of compressed storage and selling for just a few hundred dollars. Tape cartridge prices are reasonable as well, with cartridge prices in the neighborhood of $30 or less.

While tape drives are still the most popular devices for backup, CD-R (CD-Recordable) and CD-RW (CD-Rewriteable) drives are fast becoming popular backup alternatives. CD-R drives, sometimes called CD burners, can be used to create discs that can be read in just about any PC with a CD-ROM drive. These drives use a recording laser and special CD-R discs to indelibly record the information. A CD-R disc costs as little as a dollar, and can hold 650MB of data. CD-R drive prices are down to $250­$300. Most CD-R drives come with a new software program from Adaptec, called Direct CD, which makes the CD-R appear like just another hard disk, so you can simply drag and drop the files onto the icon. Backing up specific files or directories couldn't be any easier.

CD-RW drives are the latest development of the technology, and are rapidly overtaking the earlier CD-R drives in popularity. While they offer the same 650MB of storage, they can be erased and rewritten just like a standard hard or floppy disk. Prices on the media are still comparatively high, about $15 per disc. The drives themselves are about twice as expensive, in the neighborhood of $400­$500. But, as with CD-R drives, as they become more popular, prices will drop. And almost all CD-RW drives also come with Adaptec's Direct CD software. At the moment, the two most popular CD-RW drive vendors are HP, with its SureStore CD-Writer 8110, and Philips, with its OMNIWriter OMNI/20, but other vendors, including Yamaha and Ricoh, are also making inroads into this expanding market. All of these units can also create inexpensive CD-Rs.

CD technology offers several benefits as a backup device. The media can be read on any PC with a CD-ROM drive, which makes it easy to restore files when that catastrophe occurs. The CDs, once created, are pretty much impervious to shock, magnetic fields, and many other hazards. For backing up specific data files and directories, or doing incremental backups, the CD-R and CD-RW drives are hard to beat. And it takes about 35 minutes to burn 650MB onto a CD-R or CD-RW. On the downside, its 650MB size limitation makes this type of device impractical for frequent complete backups of high-capacity hard disks.

One device that seems perfect for backup is the removable media hard disk drive. A number of vendors market these, including Iomega and SyQuest. Depending on the interface, these drives can be as fast as hard disks, and range in capacity from 1GB for the Iomega Jaz and SyQuest SparQ drives to more than 4GB on the newest SyQuest drives. Backing up is as simple as copying files from one drive to another. But while these drives have speed and capacity, both desirable in a backup device, they do lack one other necessary feature--durable media. Inadvertently knocking a Travan tape or CD-R disc off the table onto the floor won't damage either. Knock a removable hard disk cartridge to the same floor, and the odds are that, at least, some part of the data will be unreadable. Or that the entire rigid disk will be knocked out of whack. The popular Iomega Zip drive uses a flexible, shock-resitant media; with a small 100MB capacity, however, it's not as practical as tape or CDs.

To Compress or Not to Compress ...

Backup capacities are frequently stated assuming the use of data compression. For example, that 10GB tape cartridge may have an uncompressed capacity of 5GB. Compression of data is most often performed with tape drives. With the newest TR-4 Travan tapes, new drives are capable of putting up to 10GB of data on a single tape. This is great for performing a complete backup on a high-capacity disk, where 8GB and even 10GB are fast becoming common.

Is compression a good idea? It depends. Compressed data isn't written differently on the tape. The compression takes place in software, before the data is written. When reading the tape on the drive on which it was created, it doesn't make any difference whether the data is uncompressed or compressed. If the drive can read the tape, the data will reliably be restored. Compressing the data just makes the backup process go a lot faster.

The uncertainties start to creep in when using a tape in a drive other than the one on which it was originally written. This can happen if the user needs to recreate the data on a different machine, or if the original drive is rendered unusable by the event that triggered the need to restore the data. On paper, tape drives of a given capacity, even from different vendors, have a great deal of compatibility. Theoretically, an 8GB Travan tape will be readable in any 8GB Travan drive, regardless of who made it. But in the real world, it doesn't always happen this way. And using compression adds another variable into the restoration equation. Maybe that Iomega Ditto drive will be able to read the compressed tape made with an HP Colorado drive. But maybe it won't. Trying to recover after a crash or disaster isn't the time to discover that the replacement drive is having problems reading the backup tapes. And some ultra-high capacity tape drives, such as AIWA's new 10GB Bolt, gain that extra capacity by using a proprietary encoding scheme. So 10GB tapes written on a Bolt drive must be read on a similar drive.

One approach is to standardize on a single brand and model of drive. Then, test tapes created in one drive under a variety of conditions and densities in other drives to discover the most reliable settings. Another approach is to vary the setting used on the backup tapes. For example, on Monday, use the highest capacity tape and make an uncompressed backup overnight. Then, on Tuesday, make a highly compressed backup. On Wednesday, just back up critical files. Thursday, start the process over again. That way, no more than one day's critical work will be lost if the tape can't be read in a different drive.

Lots of Choices, Make One

In the big picture, it doesn't much matter if the back-up option selected uses tape, CD-R, or even traditional floppy disks. The media and method are a matter more of convenience than anything else. Remember, it's the not medium, it's the data on it. Also keep in mind that backup is only one piece of the puzzle. Backup is important, and how fast and easy a particular medium is to accomplish the backup is also important. But files that later cannot be read or restored are useless.

Successful disaster recovery is all about planning and testing. If backup procedures do not currently exist, it is time to do something about it. That strategy must include a detailed recovery process with periodic testing to ensure that the files can be restored. If the recovery plan depends upon other machines or drives, the testing should make certain that the backups created, on tape or other media, can actually be read on the target systems. Thought should be given to using a variety of backup devices, with tape drives used every few days to create a complete image of a hard disk and CD-R or CD-RW used in the interim to back up specific files or directories.

Above all, a backup strategy cannot wait until disaster strikes. Starting today, valuable files should be protected in some fashion. Even if the worst happens, not all will be lost and the recovery process can begin. *

Ted Needleman was editor-in-chief of Accounting Technology for 10 years and is the author of two books, Microcomputers for Accountants and Guide to Accounting Resources on the Internet. He is currently a writer and consultant specializing in technology.