The snapshot function of LVM on the path of Linux learning

We know that LVM can elastically adjust the size of the file system, in fact, in addition to LVM can adjust the size of the file system, there is another feature is the system snapshot.

The so-called system snapshot is a moment in the file system to record the information into the snapshot area, a moment here refers to the original data is changed at the moment, the original data will be moved to the snapshot area. While other unchanged data, the snapshot area and file system are shared. So the snapshot area content is the same as the file system when you first set up the snapshot.

Because we know that only changed data is moved to the snapshot area, there is less content to save in the snapshot area.

The schematic diagram of the snapshot area is as follows:

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So how do you create a snapshot area?

To create a snapshot area using the Lvcreate-s command

Syntax format: lvcreate [option] Snapshot name/path/to/lv

-S: Create a system snapshot

-L #: Specify the space size of the snapshot

-L #: Specify the number of PE for the snapshot

-N: Immediately following the snapshot name

-P R|w: When a snapshot is created, the snapshot area has permissions

/PATH/TO/LV: Creating a snapshot area for the specified file system

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This article from the "Linux Learning Path" blog, declined reprint!