The NetBSD Logical Volume Manager

LVM is a method of allocating disk space on a disk storage devices. Which is more flexible than conventional ones. Logical Volume Manager can usually stripe, mirror or otherwise combine disk partitions to bigger virtual partitions which can be easily moved, resized or manipulated in different ways while in use. Volume Management is one form of disk storage virtualization used in Operating Systems. The NetBSD LVM has two parts user land tools and a kernel driver. Kernel driver is called devicemapper. User land part is based on Linux lvm tools developed by a community managed by Redhat inc. The Device-mapper driver can create virtual disk devices according to device table loaded to it. This table specifies which devices are used as a backend, on which offset on particular device virtual device starts. Device-mapper configuration is not persistent and must be loaded to kernel after each reboot by lvm the tools.