Disadvantages and Advantages of Replication

Replication is a data protection method that is not exactly synonymous with backup, but it accomplishes the same goal. “Replicate” literally means to copy completely, like cloning. When using replication, you are actually running a mirror copy of the data on another machine. Therefore, if one machine or one location goes down, you still have the data on the other.

Replication has its advantages and disadvantages.

Advantages:

• You can usually be sure that the mirror copy has the latest version of the files on the replicated machine.

• If you set up your network correctly, you can configure your systems to automatically change to the mirror server if the replicated server goes down.

Disadvantages:

• You need to use a greater amount of server and bandwidth resources, since the replication needs to be running either on a constant basis or very frequently in order to ensure you have the most updated versions of the files. Therefore, bandwidth may decrease at times when users need to access the network.

• You need to use another server for the mirror copy, not just another backup device or another hard disk. This requires greater expense.

Replication is similar to backup in that it copies data. However, it is very different in its implementation. Replication cannot replace backups, since backups provide important advantages that replication can’t provide. Backups allow backup media (such as tapes or discs) to be physically archived. Backup programs can have a much greater scope than replication, backing up multiple machines instead of just one. Although replication cannot be considered a complete substitute for backup, it can be used to complement backups and provide the data availability features that a backup cannot.

Frozen image backup can be considered a form of replication as well. It copies all the data, as replication does. However, frozen image does not provide the ability to restore the data to the state it was in at or very near its point of failure (unless the frozen image backup happened to be scheduled near the time of failure, by coincidence). A run-time replication means that the data is constantly getting copied over to another computer. You will usually get a “fresher” version of your data in a run-time replication than in a traditional backup or frozen image.