PV, VG, LV, PE, and Le Relationship Diagram

Several Concepts in LVM:

PV (physical volume): physical volume is at the bottom of the logical volume management system and can be partitioned on the entire physical hard disk or the actual physical hard disk.

VG (volume group): A volume is created on a physical volume. A volume group must contain at least one physical volume. After a volume group is created, it can be dynamically added to the volume group, A logical volume Management System project can contain multiple volume groups.

LV (logical volume): A logical volume is created on the basis of a volume group. unallocated space in the volume group can be used to create new logical volumes. After a logical volume is created, the space can be dynamically expanded and reduced.

PE (physical extent): The physical area is the smallest storage unit that can be allocated in the physical volume. The size of the physical area is specified when the volume group is created. It cannot be changed once determined, the physical regions of all physical volumes in the same volume group must be the same. After a new PV is added to the VG, the PE size is automatically changed to the PE size defined in the VG.

Le (logical extent): the logical region is the smallest storage unit that can be allocated in a logical volume. The size of the logical region depends on the size of the physical region in the volume group where the logical volume is located.

Volume group description area: the volume group description area exists in each physical volume, describes all information about the physical volume itself, the volume group to which the physical volume belongs, the logical volume in the volume group, and the allocation of Physical Areas in the logical volume. It is created when a physical volume is created using pvcreate.

See the attachment for the diagram.