Linux LVM Partitioning

From KdjWiki

NOTE: This is a destructive process and if you don't know (or understand) what you are doing can kill your existing setup. Please use with caution and don't blame me if you mess things up!

Contents 1 Configure Partition 2 Create the Media volume group 3 Create the Music and Video volumes 4 Using the volumes 4.1 Mount volumes 4.2 Show status 5 Management Tasks 5.1 Add Volume

Configure Partition

If we want to setup a partition (say /dev/sda4) for music and video, and we expect to need to expand it as our collection grows, we may like to use LVM to future-proof our setup. In this example, /dev/sda4 is a partition 250GB in size.

First, in fdisk, ensure the partition is type 8e (LVM):

  $ sudo fdisk /dev/sda

Enter the command t (t = change type)
Enter the partition (in our example 4)
Enter the hex code 8e (8e = Linux LVM) Enter w to write the changes and exit fdisk

Create the Media volume group

  $ sudo pvcreate /dev/sda4
  $ sudo vgcreate MediaVG -s 8m /dev/sda4

This creates a volume group called Media with a physical extent size of 8MB. If you are only going to put music (or other small-ish files here - you might want to change this to 2m or 4m).

Create the Music and Video volumes

We are going to allocate 50GB to music and 200GB to video. The music volume is going to be formatted as reiserfs and video xfs:

  $ sudo lvcreate --name music --size 50G MediaVG
  $ sudo mkreiserfs /dev/MediaVG/music

  $ sudo lvcreate --name video --size 250G MediaVG
  $ sudo mkfs.xfs /dev/MediaVG/video

Using the volumes

As you may have noticed above, the volumes are now accessed via

  /dev/MediaVG/music

and

  /dev/MediaVG/video

Mount volumes

  $ sudo mount /dev/MediaVG/music /var/music
  $ sudo mount /dev/MediaVG/video /var/video

Show status

  $ sudo vgdisplay -v

Management Tasks

Add Volume

Add volume (e.g. 200GB):

• Create partiton (/dev/hdc1) for whole disk - type 8e (LVM)
• Create physical volume: $ sudo pvcreate /dev/hdc1
• Add physical volume to the volume group: $ sudo vgextend MediaVG /dev/hdc1
• Extend music (50GB):

  $ sudo umount /var/music
  $ sudo resize_reiserfs /dev/MediaVG/music
  $ sudo mount /dev/MediaVG/music /var/music

• Extend video (150GB):

  $ sudo lvextend --size +150G /dev/MediaVG/video
  $ sudo xfs_growfs /var/video