Backup/Restore and Recovery 
Backup refers to the activity of copying files, data, or network volume, with the intention of preserving them for later use in case of hardware failure, or other disaster. When you retrieve files that have been backed up earlier, you are restoring them.
Backup and restore strategies relate to specific backup and restore solutions offered by specific vendors, therefore detailed information on various backup strategies is not discussed in this guide.
Purpose
The many reasons for backing up data include hard drives crashing, viruses infecting your system and destroying your data, human error wreaking havoc on your business, or a stolen system with your data on it.
It is important to implement a backup-and-restore strategy that protects your system against data loss, and enables you to restore the system to its correct and consistent state. The most important part of any security strategy is to backup the system at regular intervals. This means the system (files, databases, etc.) must be copied to another storage medium. When the system is damaged, the stored duplicate can be re-loaded to restore it.
For more information on a backup/restore strategy for the portal, see Portal Backup and Restore Strategy.
Prerequisites
Backup effectively contributes to safeguarding your system if it is performed as part of an overall backup-and-restore strategy. It is therefore important to carefully plan, prepare, and test the backup-and-restore system before applying it in a productive system.
In planning for backup and restore, define details for performing backups:
· What should be backed up
· When should backup occur
· Which media to use
· How to verify backups, to make sure that you have meaningful stored duplicate data that can help you to restore your systems later.
In addition, when planning your strategy, you need to take into account the following:
· Transaction workload
· Maximum permissible downtime
· Available hardware
· Amount of tolerable data loss