Relationship between hot standby and data backup of dual-machine

Some users have this problem when planning a dual-machine hot standby or dual-machine backup: I already have raid, tape backup, and do I have to do a double machine? Or is it necessary to make a tape backup if I do a dual-computer backup?

It should be said that raid and data backup are important. However, RAID technology only solves the problem of the hard disk, and the backup can only resolve the recovery after the system has a problem. And once the server itself has problems, whether it is the hardware of the device or software system problems, will cause interruption of service. As a result, RAID and data backup technologies do not solve the problem of avoiding service outages. For systems that need to provide application services consistently and reliably, it is important to have two machines. Just think, if your server is broken, how much time you need to restore it to work, and how much recovery time your users can tolerate will help you understand the importance of the two machines.

On the other hand, RAID and tape backups are also very much needed. For raid, it can greatly improve the reliability of the system at a very low cost, and its complexity is much lower than that of two machines. Because after all, the hard disk is the most frequent mechanical operation, the most vulnerable parts of the system, if the use of RAID, you can make the failure of the system is easy to repair, but also reduce server downtime to switch the number of times.

Data backup is an essential measure. Because both raid and dual, it is a real-time backup. Any software error, virus impact, misoperation, etc., will be synchronized in a number of data in the impact. Therefore, it is necessary to make a backup of the data (regardless of what media to take, it is recommended that the user should have at least an offline backup), so that the data can be corrupted, lost when the recovery.