LVM (logical volume manager) is a special Linux OS subsystem that provides additional options for managing partitions on hard disks. Unlike the classical scheme, when partitions that are used for file systems are created on every disk, LVM allows for combining the space on different disks into a common logical space, which can then be used to create or expand partitions. Thus, with help of LVM, one can place one partition on multiple disks or place multiple partitions on one disk.