Mirror Backup
In many respects a mirror backup is the same as a full backup, the only difference is that the files and folders are not password protected or compressed. The reason that this backup method may be wanted is that it provides a very simple way to browse the data. This method is the fastest way to backup all the data, as compression can take a significant amount of time, unfortunately this method takes up more space and offers no protection from data theft. The mirror backup strategy is different from the other backup strategies in that it does not create one backup instead, it copies the file and folder structure exactly and puts it in the backup location. It is so easy to access the backup version that there is not real restoration needed. This can be especially useful where only one file backup was needed, rather than having to copy over all the data in a restoration just to retrieve one file. As there is no password protection possible on the backup, instead security could be provided by limiting access to the drive the data is present on, or to secure the disks physically with a lock if it is on a DVD for example.
Advantages of mirror backup
- Faster backup than full backup
- Instant access to the backup data without any decompression
Disadvantages of mirror backup
- Needs the most storage
- Password protection is not possible
Improvements which some software vendors do to mitigate the disadvantages
Some vendors offer an option to mirror to a mirror backup but to only to copy over the changes to the mirror. Note though that the disadvantage to this is that if there is an unnoticed corruption with the current data then the mirror backup will also end up containing the corruption.