The difference between hot standby and RADE

Some users have the problem when planning dual-system hot backup or dual-system backup: I already have RAID, and tape backup, and do I have to do dual-machine? Or, if I do a two-machine backup, is it necessary to do a tape backup?

It should be said that RAID and data backup are very important. However, RAID technology can only solve the problem of the hard disk, and the backup can only solve the recovery after the system has a problem. Once the server itself has a problem, whether it is a hardware problem of the device or a problem with the software system, the service will be interrupted. Therefore, RAID and data backup technologies cannot solve the problem of avoiding service interruption. For systems that need to continuously and reliably provide application services, dual-machine is still very important. Just think about it, if your server is broken, how much time you have to restore it to work, and how long your recovery time can be tolerant to understand the importance of the dual machine.

On the other hand, RAID and tape backup are also very much needed. For RAID, the reliability of the system can be greatly improved at a very low cost, and its complexity is far lower than that of the dual-machine. Because after all, the hard disk is the most frequently operated and vulnerable part of the system. If RAID is used, the faulty system can be easily repaired and the number of server shutdowns can be reduced.

Data backup is an essential measure. Because RAID or dual-machine is a real-time backup. Any software errors, virus effects, misuse, etc., will affect all of the data simultaneously. Therefore, it is important to back up the data (regardless of the media, it is recommended that the user have at least one offline backup) in order to recover from data corruption and loss.