Creating volume groups and assigning physical volumes (vgcreate -s, vgextend, vgs)

A volume group (VG) is the storage pool in LVM. It combines the space of one or more physical volumes into a single pool, from which you allocate logical volumes. Because a logical volume draws from the pool rather than a single disk, it can be larger than any one device, and you can grow the pool later simply by adding another physical volume.