lvm

Linux's Logical Volume Manager, or lvm, is a method for dividing a physical disk (or physical volume, PV) into blocks (or physical extents, PE). These blocks can be assigned to partitions (or logical volumes, LV). The process of assigning PE’s to a LV creates a map for translating PE’s to LE’s, called the allocation map. The purpose of this abstraction of disk blocks is to create great flexibility when it comes to allocating disk space to partitions....