volumegroup

A volume group (VG) is a fundamental element of the Linux Logical Volume Manager (LVM). It represents a pool of storage created by combining one or more physical volumes (PVs) such as disks or partitions. The VG provides a single, flexible space from which logical volumes (LVs) are allocated and resized as needed.

Within a volume group, space is divided into physical extents (PEs) of a fixed size, enabling dynamic and efficient allocation. The VG maintains metadata that records its name, UUID, the PVs it contains, and the amount of free space. LVs carved from the VG are the actual usable block devices that host filesystems or swap areas.

Volume groups are managed with LVM tools, allowing storage to be added by attaching new PVs, removed, or resized. They also support features such as thin provisioning and snapshots via LVM. A typical workflow is to create a VG from PVs, create LVs from the VG, and resize LVs or the VG as storage needs evolve.

Common operations and concepts include:

- Create a volume group: vgcreate VGName PV1 [PV2 ...]

- Extend a volume group: vgextend VGName PVn

- Reduce or remove a PV from a VG: vgreduce VGName PV

- Remove a volume group: vgremove VGName

- Display information: vgdisplay VGName

- Manage logical volumes: lvcreate, lvresize, lvremove, among others

See also: Logical Volume Manager, Physical Volume, Logical Volume.