The size of a Volume Group (VG) isn't a fixed value; it's determined by the combined size of the Physical Volumes (PVs) that make up the VG. The number of PVs a VG can contain also varies depending on the type of VG.
Here's a breakdown:
- Basic Volume Group: Can contain 1 to 32 Physical Volumes. The total size depends on the size of each PV.
- Big Volume Group: Can contain 1 to 128 Physical Volumes. This allows for a larger overall VG size.
- Scalable Volume Group: Can contain up to 1024 Physical Volumes, offering the greatest potential VG size.
Therefore, the "VG size" is best understood as the sum of the sizes of all Physical Volumes assigned to that Volume Group.
To illustrate:
If you have a Volume Group named "vg01" composed of three Physical Volumes:
- /dev/sda1 (500GB)
- /dev/sdb1 (1TB)
- /dev/sdc1 (2TB)
Then the size of "vg01" would be 500GB + 1TB + 2TB = 3.5TB.
In summary: VG size is dynamic and dependent on the sizes and quantity of physical volumes assigned to it, within the limitations of the VG type.
