The importance of data
- Business dependence on IT systems is growing
- Data are important assets of the government, enterprises, research institutions
- More and more data and more important
- The underlying hardware platform failures often result in service interruption
- Construction of a large number of underlying hardware point of failure risks
Data protection category is very broad, from a technical point of view, to establish a data protection system, key steps and issues to consider include data consistency and integrity, to extract production data, data transfer bandwidth, data transmission security, data recovery , copy of the data storage media; from the implementation point of view, there are copy, backup, copy, snapshot, mirroring; implement position from the point of view, it may be implemented in the host layer, the network layer, the storage layer.
To achieve levels of data protection
Backup divided into three types: full backup, incremental backup, differential backup
Incremental backup: Backup to do a full backup or incremental backup after modifying the file.
The advantage is the small amount of data backup, shorter backup windows; drawback is that multiple copies of backup data requires data recovery, greater risk of problems
Differential backup: backup after the last full backup changed files. The advantage is fast recovery speed by a full backup and the last differential backup to complete recovery recently, the disadvantage is the long time required for backup.
Backup mode
Backup mode, four kinds: LAN backup, LAN FREE backup, SERVER FREE backup, SERVER LESS backup networking architectures and the difference lies in the data stream.
LAN backup is the backup we usually use the computer, such as backup files on our system to other computer, the data stream of this backup method is backed up, the disadvantage is IO performance can affect computers via the LAN network and LAN network.
LAN FREE talking SAN network, we know them SAN network server generally has two network cards, a tube business, another pipe storage, backup time so that only the storage network is busy, the service network will not be affected, Although the liberation of the LAN network, but when backing up large amounts of data stream still flows through the business server so that the server business is more busy, and will affect the performance of the server.
Then appeared SERVER FREE, SERVER FREE is also used in a SAN network, LAN FREE with different data streams are not flowing through the business server, will only flow through the backup server storage between storage, backup application server is only responsible to send instructions to the server.
SERVER LESS on a more thorough, SERVER FREE just the liberation of the server business, and the pressure placed on the backup server, and SERVER LESS backup data streams are not flowing through the task server, but stored in the memory, the point to point, Thus the server need only send the next instruction.
