LVM

LVM (Logical Volume Manager) is a software which uses physical devices abstract as PVs (Physical Volumes) in storage pools called VG (Volume Group). Whereas physical volumes could be a partition, whole hard drives grouped as JBOD (Just a Bunch Of Disks) or complete RAID systems.

Installation
First we need to enable the device mapper in our kernel:

is available on Gentoo Linux and supports the following useflags:
 * clvm = Allow users to build clustered lvm2
 * cman = Cman support for clustered lvm
 * lvm1 = Allow users to build lvm2 with lvm1 support
 * nolvmstatic = Allow users to build lvm2 dynamically
 * readline = Enables support for libreadline, a GNU line-editing library that almost everyone wants
 * static-libs = Build static libraries

The package comes with a start-stop-daemon, which we start and add to the boot runlevel:

Usage
LVM organizes storage in three different levels as follows:
 * hard drives, partitions, RAID systems or other means of storage are initialized as PV (Physical Volume)
 * Physical Volumes (PV) are grouped together in Volume Groups (VG)
 * Logical Volumes (LV) are managed in Volume Groups (VG)

Links

 * lvm2
 * LVM tldp.org