.. -*- coding: utf-8; -*-
.. include:: HEADER.rst

=====
 LVM
=====
.. contents::
   :local:

Debian package
==============
::

  $ sudo apt-get install lvm

List partitions
===============
::

  $ sudo sfdisk -l

or use gparted(1).

Setup physical volume
=====================
::

  $ sudo pvcreate /dev/sdc3
  Physical volume "/dev/sdc3" successfully created

Setup volume group
==================
::

  $ sudo vgcreate vg0 /dev/sdc3
  Volume group "vg0" successfully created

Show info about volume group
============================
::

  $ sudo vgdisplay
  --- Volume group ---
  VG Name               vg0
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               77.22 GB
  PE Size               4.00 MB
  Total PE              19769
  Alloc PE / Size       0 / 0
  Free  PE / Size       19769 / 77.22 GB
  VG UUID               ZOQvrP-PnJ2-kKsH-7aLU-eOa3-K5M2-sRstJH

Create logical volume
=====================
::

  $ sudo lvcreate -L 10G -n home vg0
  Logical volume "home" created

Show info about logical volume
==============================
::

  $ sudo lvdisplay
  --- Logical volume ---
  LV Name                /dev/vg0/home
  VG Name                vg0
  LV UUID                XWJFnF-LjQg-Xsvm-IeQI-68mX-jiYd-pSpA00
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                20.00 GB
  Current LE             5120
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           254:0

  --- Logical volume ---
  LV Name                /dev/vg0/swap
  VG Name                vg0
  LV UUID                BHBQd0-1RlO-hHn7-jAij-Gyg6-KnqE-lRBgPY
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                1.00 GB
  Current LE             256
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           254:1

Create fs on logical volume
===========================
::

  $  sudo mke2fs -j /dev/vg0/home
  mke2fs 1.40-WIP (14-Nov-2006)
  Filesystem label=
  OS type: Linux
  Block size=4096 (log=2)
  Fragment size=4096 (log=2)
  1310720 inodes, 2621440 blocks
  131072 blocks (5.00%) reserved for the super user
  First data block=0
  Maximum filesystem blocks=2684354560
  80 block groups
  32768 blocks per group, 32768 fragments per group
  16384 inodes per group
  Superblock backups stored on blocks:
          32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

  Writing inode tables: done
  Creating journal (32768 blocks): done
  Writing superblocks and filesystem accounting information: done

Remove logical volume
=====================
::

  $ sudo lvremove  /dev/vg0/home

Move home dir to lvm
====================
::

  $ su
  ...
  $ mv /home /home2
  $ lvcreate -L 10G -n home vg0
  $ mke2fs -j /dev/vg0/home
  $ emacs /etc/fstab
  ...
  $ cat /etc/fstab
  ...
  /dev/vg0/home   /home  ext3  defaults  0  2
  ...
  $ mount -a
  $ (cd /home2; tar -cf - .) | (cd /home; tar -xpf -)
  $ rm -r /home2

Creating swap on lvm
====================
::

  $ su
  ...
  $ lvcreate -L 1G -n swap vg0
  $ mkswap -v1 /dev/vg0/swap
  $ emacs /etc/fstab
  ...
  $ cat /etc/fstab
  ...
  /dev/vg0/swap   swap  swap  defaults  0  0
  ...
  $ swapon -a