Purpose of full disk mirroring

The purpose of a full disk image is roughly a few:

1, the non-Windows operating system or industrial control system for backup to achieve migration or when the operating system is damaged after the restoration.

2, the bare partition, encrypted partition or informal partition for backup.

3, backup data, I hope it is easy to retain the original character set state, permissions, security description.

4, iSCSI disk, San disk, virtual machine virtual disk and physical hard disk to do system testing, migration can take advantage of this method.

5, when the source storage media in an unstable state, in order to rename the further spread of unstable state, do a full backup. This is sometimes better than copy, because copy reads a sector (such as the node area, the main directory, and so on) multiple times, and if the sectors are unstable or are just in the magnetic information unstable area, copy may cause the hard drive to damage quickly.

6, the data migration. When there is a large amount of files in the source media, it is close to total space and the number of files is very high. Regular copy or tar can take a lot of time (because the file system is repeated recursively), and if you use mirroring, it's not a file, it's a continuous read, and Io is much faster. A simple experience, if a Windows partition, size 100G, put millions of or tens of thousands of files, if copy may not be completed in a day, but if it is a full partition mirror, on the normal server may be less than half an hour.

7, forensics function. A lot of computer forensics is necessary to the original plate for the full evidence.

8. Provide a copy for recovery in data recovery. In many cases, the source device's data fails (data deletion, data loss, file system exceptions, database exceptions, etc.), but the device will continue to work (for example, the service will run, or the data is stored on a LUN), can not directly deal with the device, you need to save the state as soon as possible, This is what a full mirror does.

9, data recovery in order to ensure data security, mirroring provides redundancy. Especially important data, if you need to do data recovery, worry about the physical or logical damage to the source media during the recovery process, you may need to do a full mirror copy to ensure foolproof.

10, data recovery, if some of the structure contains physical bad sector, cannot be repaired. You can mirror to another piece of good media, and then fix those bad structure.

11, other.

Backup mode See:

How do I complete a full image of the hard drive? http://zhangyu.blog.51cto.com/197148/138974