• PC World
• »Storage
• »Hard Drives

There are two types of businesses: those which have experienced the gut-wrenching loss of valuable computer data, and those which will.

Unfortunately, not all businesses take adequate precautions to protect their operations from data loss. According to a recent Office Depot publication on disaster preparation strategies for small businesses, 20 percent of them do not back up their data. The study states that a company that cannot access its business data for longer than 48 hours is unlikely to fully recover from the outage.

Home Backups not Suitable

A weekly or monthly data backup may be entirely adequate for a home PC, but it falls short when it comes to protecting business data. While a home user may be inconvenienced by losing a few days' worth of e-mail messages and having to wait three or four days for a PC to return from the repair depot, a business will suffer more severe financial consequences.

If a business has no way of entering customer sales orders, issuing invoices, or managing its operations without access to its computer data, any outage that lasts more than a few hours will deliver a blow to the bottom line. How can you protect your business from this loss without spending a fortune?

The Perfect Data Backup

A perfect data protection technique should back up data speedily, conveniently, automatically, and at a reasonable cost. It should safeguard against all reasonably possible causes of data loss, from the failure of a single hard drive to a fire that destroys the office and the computers within it.

A RAID (redundant array of inexpensive, or independent, disks) setup can back up data quickly, in the blink of an eye. But RAID doesn't protect against accidental deletion of data, nor does it safeguard against a disaster that destroys an entire computer, such as a flood.

Daily backups to a tape drive or to an external hard drive provide some protection against accidental deletion of data. However, this technique backs up less frequently and requires more time to complete--sometimes several hours--than RAID. Also, it still doesn't help if a disaster destroys your building.

Periodic rotation and transport of backup tapes or external hard drives to offsite storage will protect against theft or destruction of the premises. But physical shuffling of storage media is neither convenient nor automatic.

Internet-based systems that transmit backups to remote data centers are convenient and can be configured to operate automatically. However, if your business has dozens of gigabytes of important data, a full backup can take days to complete, even over a broadband Internet connection. Monthly service fees can be pricey.

Combining Backup Techniques

If there's no one perfect data backup technique, do you just throw up your hands and hope a disaster will never strike?

Not at all. You can build a good data backup system by using more than one technique. This belt-and-suspenders approach to data protection relies on the strengths of one backup technique to offset the weaknesses of another.

Implementing multiple backup techniques will cost more than using just one. However, the value of your business data will almost certainly justify the additional cost.

Fast, Affordable RAID

I'll be addressing different backup options in more detail over several columns. But for immediate and constantly renewed data backup I can think of nothing better than using a RAID array of hard drives to store both data and important programs on your server or PC.

RAID is less expensive and easier to set up than ever. Until recently, you needed to purchase a special card to set up a hardware-based RAID array. In addition, migrating to a RAID array from an existing hard drive involved a not-insignificant risk of data loss.

Now, many new PCs come with a drive controller with RAID capabilities, whether or not it is advertised. Computer makers don't often undersell and over-deliver in this way, but I believe some do so in this case because they are concerned about the cost of supporting RAID migrations.

Intel Matrix Storage

Intel's hardware-based implementation of RAID works with recent versions of Microsoft Windows including 2003 Server, XP, and Vista. A number of popular hard drive controllers made by the chip-making giant support the technology.

To implement Intel's RAID, you must install at least one additional hard drive and load Intel Matrix Storage Console management software, which you can download for free from Intel's Web site. The site lists the supported drive controllers and includes complete installation instructions.

Fault-Tolerant RAID

A comprehensive discussion of all RAID options is beyond the scope of this column. But make sure to select a method that offers fault tolerance through data redundancy, such as RAID 1 (often called mirroring), RAID 5, or RAID 10. RAID 0, sometimes called data striping, provides no safeguards for your data; rather, it's intended to improve performance.

Implementing RAID 1 requires adding an additional hard drive of equal or greater storage capacity than the drive you already have on the PC or the server you wish to back up. If you have one 250GB hard drive, for example, you'll need to install another with at least 250GB capacity. These days, such drives are relatively inexpensive (see our latest top 10 internal hard drives chart).

Intel's Matrix Storage Console makes it easy to migrate from a standard single hard drive to a RAID 1 array with two hard drives, within 3 hours. Data on the existing hard drive is preserved. You can continue to use the PC during the RAID migration, though operations will be slower until the process is complete.

RAID 1 can noticeably improve data-retrieval performance for dual-core PCs, since information can be retrieved from either mirrored hard drive. There is no significant improvement when saving data, however. The only RAID migration drawback I have noticed is that you may need to reregister some apps, such as Adobe's Creative Suite.

When a Good Hard Drive Goes Bad

If one hard drive crashes in a fault-tolerant RAID setup, its data is safely stored on the other hard drive(s) in the array. It's a simple matter to restore normal operations.

Recently my computer froze after one hard drive failed in a RAID 1 array. Rebooting the computer required more time than usual, almost 15 minutes. However, the second hard drive took over and the computer operated normally, with no evidence of data loss.

To restore the data protection offered by RAID, I needed to install another hard drive to replace the failed device.

RAID Rocks

Performance-wise, it's hard to beat the ability to return to normal computer operations after a hard drive failure in just 15 minutes. My added cost for RAID protection was about $100 for the second hard drive and cables.

I will discuss complementary backup techniques that offset RAID's weaknesses in a future column.

Richard Morochove is an IT consultant and writer. Send him questions about using technology in your small to mid-sized business via e-mail. PC World may edit your query and cannot guarantee that all questions will be answered.