Understanding backup methods and their advantages

Before you can develop your media rotation strategy, you will need to decide whether you want to perform only full backups or use a strategy that includes Full backups and one of the modified backup methods (differential, incremental or working set backups).

The backup methods used by Backup Exec are as follows:

There are advantages and disadvantages to each backup method.

Table: Backup Method Advantages and Disadvantages

Method

Advantages

Disadvantages

Full

  • Files are easy to find - Since full backups include all data contained on a device, you don't have to search through several media to find a file that you need to restore.

  • There is always a current backup of your entire system on one media or media set - If you should need to restore your entire system, all of the most current information is located on the last full backup.

  • Redundant backups - since most of the files on your file server rarely change, each full backup following the first is merely a copy of what has already been backed up. This requires more media.

  • Full backups take longer to perform - Full backups can be time consuming, especially when you have other devices on the network that need to be backed up (e.g., agent workstations, remote servers).

Differential

  • Files are easy to find - Restoring a system backed up with a differential strategy requires a maximum of two backups - the latest full backup and the latest differential backup. This is less time consuming than backup strategies that require the latest full backup and all incremental backups created since the full backup.

  • Less time required for backup and restore - Differential backups take less time to restore than full backups. Faster recovery is possible in disaster situations because you only need the latest full and differential backup media to fully restore a device.

  • Redundant backups - All of the files created or modified since the last incremental backup are included; thus creating redundant backups.

Incremental

  • Better use of media - Only files that have changed since the last backup are included, so there is much less data storage space required.

  • Less time required for backup - Incremental backups take much less time than full and differential backups to complete.

  • Backups are spread across multiple media - Since multiple media is required in a disaster situation, this can cause recovery of a device to take longer. In addition, the media must be restored in the correct order to effectively bring the system up to date.

Working Set

  • Restoring a system backed up with a working set strategy requires only the media containing the latest working set backup media and the media containing the most recent full backup.

  • You can perform a working set backup, restore the data to a new system, and be up and running faster than if you had to restore a full backup followed by all of the incremental or differential backups.

  • Working set backups take less time to run than full backups.

  • The Last accessed in (x) days method is available only on platforms that support the last accessed date (Windows, NetWare, and UNIX). Working set backups will work as differential backups when selected for other platforms.


Объявления: