Backup Procedures

A Backup Article Contributed by Pearlyn Williams

Backup - a Protection Against File Losses

Persons who have worked for a long time with computers and learned the benefit of backup will warn you that, sooner or later, you will lose some critical files. Even a small brownout can cause the heads on your computer's hard disk to lose its balance and crash onto the disk surface, just at the precise moment when you were about to remember to backup your thesis, that was already a week overdue. That's just how it is in the computer environment - file losses are a constant threat.

The Solution is Backup

Fortunately, here comes backup to the rescue. Creating backup means making a duplicate versions of files that are critical, so that what would have been a major disaster become only a minor irritant. The backups that are created through a file-copy, disk-copy, or backup command can be on diskette, hard disk, tape, CD-R, DVD-R, or virtually any other secondary storage medium.

Types of Backup

A popular type of backup that is practised is making a duplicate of a long file that is being developed in memory. For instance, suppose you are putting together your thesis using Microsoft Word. It is good to make a habit of saving the document onto disk every ten or fifteen minutes. To backup several files at the same time, many different strategies can be used. For example, full backups, which store all files from their hard disks onto tapes or disk cartridges at the end of every day or week.

There are, however, advantages and disadvantages. The advantage of a full backup is that it is more or less straightforward. The disadvantage is that it takes up more storage space and takes longer than when just selected files are backed up.

Backup Choices

The alternative to a full backup is a partial backup where you only the files that have been created or altered since the last backup, are copied. The experts often use two such types of partial backup procedures: differential and incremental backups. Differential backup copies all files created or changed since the last full backup. With an incremental backup, copies are made of files created or changed since the last backup of any type.

Both the differential and incremental backups enable you to reconstruct the hard disk if it becomes corrupted, when used along with the copy of the full backup. The faster of the two backups to perform is the Incremental backup, but it results in more work to fully reconstruct the hard disk if it fails. It is more common for persons with hard disks to perform partial backups daily and full backup a weekly.

Securing Backup Files

It is a good practice when backing up files on a disk, to always ensure that the backup files are placed on a different disk from the originals. Furthermore, it is essential that these copies are never kept in the same room or building. This is a good way to ensure that in the case of a serious accident such as a fire or flood, the backed up copies will be safe and secure offsite, and readily available to help in the recovery process.