In computer storage, logical volume management or LVM is a method of allocating space on mass storage devices that is more flexible than conventional partitioning schemes. In particular, a volume manager can concatenate, stripe together or otherwise combine partitions into larger virtual ones that can be resized or moved, possibly while it is being used.
Volume management is one of many forms of storage virtualization, the one implemented as a layer in the OS disk driver stack.
Reference:
http://en.wikipedia.org/wiki/Logical_volume
