2/24/01 Backup.html

Backing up your data is an important thing to do. Computers do crash and the worst case is a hard disk mechanical failure. You could lose everything on your hard drive if that happens. Here are a few methods and their advantages and dis advantages.

The most often sited reason that a backup wasn't made is: "It takes too long!" So the key to a good backup strategy is top make it as quick and painless as possible.

The old way was to set up a scheduled tape backup so that it runs at night and pick up the finished tape in the morning. That was fine when hard disks were under 10 gigabytes and everything would fit on one tape. Who cared how long it took> As long as the power didn't go out you could have a copy of everything, every day. But sequential media, by it's nature is slow to record to and retreive from. If you ever had to recover a file from tape it can take hours.

Now days, many customers have networks. It is easier to copy from one disk to another across the network so that there are two copies of valuable data if something happens. Recently I have discovered a utility called XXCOPY that allows for backups of all files including hidden and system files. It can be set up to copy only files that have changed since the last backup. It compares date, time, and file size to determine if a backup is needed. I recently used it to backup 3.5GB of data. It initiallt took 2 hours to make the first image and only 10 minutes to backup what had changed. So once it was set up, it only took 10 minutes. That's my kind of backup! When coupled with removable disk drives, this method could be used to take data off premise or lock it in a fireproof vault.

Disk mirroring or RAID-1 is also now possible on Windows machines without buying server software. When coupled with removable disks this is also a very good method. Two copies of everything are being written to two separate disks all the time, At the end of the day, you remove the current second drive and store it and insert yesterdays backup. The system remirrors to todays data and you are ready to record more data. The disadvantage of this method is that if you close your accounting month wrong, the error is instantly written to both working copies. To restore, you need to take the machine apart to insert yeaterdays backup as the new master. Considering how infrequently that data must be restored, usually less often than once a year, this may be an OK strategy.

Making some decisions about which is the most critical data may allow you to backup just that data on removable media,(ZIP drive, Jaz, Syquest, CDRW, or whatever) and get it off premise in a short time. I have a client who backs up their accounting system data files every night on a ZIP disk and takes it home. Yes, if the building burned, or the machine was stolen, it would take a while to reinstall all the software, but the data (Accounts Receivable, Payable, ...) are all safe. This client also periodically makes a more inclusive tape backup over night so that they will have all the programs and correspondance.

There are some products on the market, such as Power Quest's Drive Image that will copy your entire drive in a compressed format to another device or removable media. My only concern for these products is that customers clearly understand the method that should be used to restore a few files from one of these backups. Most commonly, it's only a few files that are really needed unless there is a mechanical failure of a hard disk. To protect against this worst case, be sure your backups are going to another physical drive, not just another partition on the same drive. If you don't know what I mean then you had better find out. Doing it wrong can make your backup efforts worthless.

Last but not least, for the desparate and unprepared, there is data recovery. This involves sending your disk away to a company ( On Track is the largest) that can disassemble it and analyize what is recorded on the platters and send back what it can understand to you on CDR, tape, or another hard disk. This process is expensive, time consuming, and doesn't usually get it all back. Virus damage, or drive mechanical failure are the two most common causes of a ride to data recover for your drive. It is to be avoided. I suggest you choose one or a combination of methods above to avoid it.