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This article mainly explains "what is the difference between disaster recovery and backup". The content of the explanation in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought. Let's study and learn "what are the differences between disaster recovery and backup"?

What is disaster recovery?

Disaster recovery system refers to the establishment of two or more IT systems with the same function in distant places, which can monitor health status and switch functions between each other. When one system stops working due to accident (such as fire, earthquake, etc.), the whole application system can be switched to another place, so that the function of the system can continue to work normally.

Disaster recovery technology is a part of the high availability technology of the system. Disaster recovery system puts more emphasis on dealing with the impact of external environment on the system, especially the impact of catastrophic events on the entire IT node, and provides node-level system recovery functions.

Classification of disaster recovery

According to the degree of protection to the system, the disaster recovery system can be divided into data disaster recovery and application disaster recovery. Data disaster recovery refers to the establishment of a remote data system, which is a real-time replication of local key application data.

On the basis of data disaster recovery, application disaster recovery is to establish a complete backup application system (which can backup each other) which is equivalent to the local production system in different places. In the case of disaster, the remote system quickly takes over the operation of the business. Data disaster recovery is the guarantee against disasters, and application disaster recovery is the goal of disaster recovery system construction.

What is the relationship between disaster recovery and backup?

Disaster recovery backup is actually two concepts, disaster recovery is to ensure the normal operation of the information system in the event of disasters, to help enterprises achieve the goal of business continuity, backup is to deal with the problem of data loss caused by disasters. Before the emergence of integrated disaster recovery and backup products, disaster recovery system and backup system were independent. The ultimate goal of disaster recovery backup products is to help enterprises deal with "soft" disasters such as human misoperation, software errors and virus intrusion, as well as "hard" disasters such as hardware failures and natural disasters.

The difference between disaster recovery and backup

Generally speaking, backup refers to data backup or system backup, while disaster recovery refers to data backup or application system backup that is not in the same computer room. Backup is implemented by backup software technology, while disaster recovery is achieved by replication or mirror software. the fundamental difference between the two is:

Disaster recovery is mainly aimed at fires, earthquakes and other major natural disasters, so a certain safe distance must be ensured between the backup center and the main center; data backup is carried out in the same data center.

Disaster recovery system not only protects data, but also ensures business continuity, while data backup system only protects data security.

Disaster recovery ensures the integrity of the data; backup can only recover the data before the backup time point.

Disaster recovery is an online process; backup is an offline process.

In the disaster recovery system, the data of the two places are real-time consistent; the backed-up data has a certain timeliness.

In the case of failure, the switching time of the disaster recovery system is from a few seconds to a few minutes, while the recovery time of the backup system may be from several hours to dozens of hours.

Classification of disaster recovery

1. Data level

Data-level disaster recovery is the most basic means, which means that through the establishment of remote disaster recovery centers and remote backup of data, it is necessary to ensure that the original data will not be lost or destroyed after a disaster, but at the level of data-level disaster recovery, the application will be interrupted in the event of a disaster. This disaster recovery method can be simply understood as a remote data backup center, that is, to establish a data backup system or a disaster recovery system, such as databases, files and so on.

Advantages: low cost, relatively simple construction and implementation

Disadvantages: the recovery time of data-level disaster recovery is long.

2. Application level

On the basis of data-level disaster recovery, application-level disaster recovery is to build a set of the same application system at the backup site, through synchronous or asynchronous replication technology, which can ensure that the key applications can resume running within the allowable time range. minimize the loss caused by the disaster, so that users basically do not feel the occurrence of the disaster. Application-level disaster recovery is to establish an application backup system, such as an OA system is running, in another place to build a set of the same OA system.

Advantages: the services provided are complete, reliable and secure to ensure business continuity

Disadvantages: the cost is high and more software is needed.

3. Business level

Business-level disaster recovery is the disaster recovery of the whole service, which requires not only the necessary IT-related technologies, but also all the infrastructure.

Advantages: ensuring business continuity

Disadvantages: the cost is very high, and it also needs the input of the place cost, so it is difficult to implement.

Backup level

Disaster recovery backup is through the establishment and maintenance of a backup storage system in different places, using geographical separation to ensure the ability of the system and data to resist catastrophic events. According to the degree of disaster resistance of disaster recovery system, it can be divided into data disaster recovery and application disaster recovery. Data disaster recovery refers to the establishment of a remote data system, which replicates the key application data of the local system in real time.

When there is a disaster, the remote system can quickly replace the local system to ensure business continuity. Application disaster recovery is at a higher level than data disaster recovery, that is, to establish a complete backup application system in different places, which is equivalent to the local data system (can backup each other with the local application system or work with the local application system).

After the disaster, the remote application system quickly takes over or undertakes the business operation of the local application system. To design a disaster recovery backup system, many factors need to be considered, such as the amount of backup / recovery data, the distance between the application data center and the backup data center and the mode of data transmission, the recovery speed required in the event of a disaster, the management and investment of the backup center, and so on. According to these factors and different applications, disaster recovery backup can usually be divided into four levels.

Level 0: no backup center

This level of disaster recovery backup actually has no disaster recovery ability, it only backs up the data locally, and the backed up data is only saved locally, not sent to other places.

Level 1: local tape backup, remote storage

Back up critical data locally and send it to a different location for storage. After the disaster, restore the system and data according to the predetermined data recovery procedure. This scheme is low-cost and easy to configure. However, when the amount of data increases, it is difficult to manage the storage media, and when a disaster occurs, it is difficult to recover a large amount of data in time. In order to solve this problem, when a disaster occurs, critical data is recovered first, and then non-critical data is restored.

Level 2: hot backup site backup

Set up a hot backup point in different places and back up the data through the network. That is, through the network in a synchronous or asynchronous way, the data of the main site is backed up to the backup site, the backup site generally only backs up the data and does not undertake the business. When there is a disaster, the backup site takes over the business of the main site, thus maintaining the continuity of business operation.

Level 3: activity backup centre

Set up two data centers far apart, both of which are working and back up each other's data. When a disaster occurs in one data center, another data center takes over. According to the actual requirements and the amount of money invested, this level of backup can be divided into two types:

1. The backup of critical data between the two data centers is limited to each other

2. The two data centers mirror each other, that is, zero data loss, etc.

Zero data loss is currently the most demanding way of disaster recovery backup, it requires that no matter what disaster occurs, the system can ensure the security of data. Therefore, it needs to configure complex management software and dedicated hardware equipment, the investment is relatively large, but the recovery speed is also.

Thank you for your reading. the above is the content of "what's the difference between disaster recovery and backup". After the study of this article, I believe you have a deeper understanding of the difference between disaster recovery and backup. Specific use also needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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