Backup Types

A Backup Article Contributed by Anand R

Backup Types

Deciding which type of backup to use depends on your organization's needs. The two major considerations are the value of the data and the amount of data that has changed since the last normal or incremental backup. There are many ways to provide the backup solutions.

Normal Backup

A normal backup copies all selected files and marks each as having been backed up. Normal backups are the easiest to use for restoring files because you need only the most recent backup file or tape to restore all of the backed up files. Normal backups take the most time because every file that is selected is backed up, regardless of whether it has changed since the last backup. This could be used for internet backup, disk backup, hard drive or file backups.

Incremental Backup

An incremental backup reduces the time required to complete the backup process by saving only files that have been created or changed since the last normal or incremental backups. It marks files so that you will know if a specific file has been backed up. You need to create a complete normal backup of your system before you can run incremental backups.

If you use a combination of normal and incremental backups to restore your data, you must have the last normal backup set of media as well as every incremental backup in chronological order since the last normal backup Tape back up suits this Server backups are generally Incremental.

Differential Backup

A differential backup can reduce the time required to complete the backup process by copying files that have been created or changed since the last normal or incremental backup. It does not mark files as backed up. You need to create a complete normal backup of your system before you run differential backups. If you use a combination of normal and differential backups, you must have the last normal backup media set and the last differential backup sets to restore your data.

Copy Backup

A copy backup copies all selected files, but it does not mark each copied file as backed up. Copying is a useful temporary method to back up files between normal and incremental backups; it does not affect other backup operations.

Daily Backup

A daily backup copies all selected files that have been modified on the day that the daily backup is performed. The backed up files are not marked as backed up. This helps in case of any hard disk crash.

Archive Attribute

Some backup types use a backup marker, also known as an archive attribute, to track when a file has been backed up. When the file changes, Operating system marks the file to be backed up again. Files or directories that have been moved to new locations are not marked for backup. Backup allows you to back up only files with this marker set and to choose whether or not to mark files when they are backed up. Microsoft back ups are based on the archive attribute.