Logical Volume Manager
The set of operating system commands, library subroutines, and other tools that allow you to establish and control logical volume storage is called the Logical Volume Manager (LVM).
The LVM controls disk resources by mapping data between a more simple and flexible logical view of storage space and the actual physical disks. The LVM does this using a layer of device-driver code that runs above traditional disk device drivers.
The LVM consists of the logical volume device driver (LVDD) and the LVM subroutine interface library. The logical volume device driver (LVDD) is a pseudo-device driver that manages and processes all I/O. It translates logical addresses into physical addresses and sends I/O requests to specific device drivers. The LVM subroutine interface library contains routines that are used by the system management commands to perform system management tasks for the logical and physical volumes of a system.