Chapter 3. Deploying LVM

The following procedures represent the basic configuration for LVM logical volumes on a freshly installed operating system.

3.1. Creating LVM physical volume

This procedure describes how to create and label LVM physical volumes (PVs).

Prerequisites

  • The lvm2 package is installed.

Procedure

  1. To create multiple physical volumes, use the space-delimited device names as arguments to pvcreate command:

    # pvcreate /dev/vdb1 /dev/vdb2

    This place a label on /dev/vdb1 and /dev/vdb2, marking them as physical volumes belonging to LVM.

    For more information, see pvcreate man page.

3.2. Creating LVM volume group

This procedure describes how to create an LVM volume group (VG).

Prerequisites

Procedure

  1. To create a volume group, use the following command:

    # vgcreate myvg /dev/vdb1 /dev/vdb2

    This creates a VG with the name of myvg. The PVs /dev/vdb1 and /dev/vdb2 are the base storage level for the VG myvg.

    For more information, see vgcreate man page.

It is possible to extend the above VG with the PVs later. To extend a VG, use the following command:

# vgextend myvg /dev/vdb3

3.3. Creating LVM logical volume

This procedure describes how to create LVM logical volume (LV).

Prerequisites

Procedure

  1. To create a logical volume, use the following command:

    # lvcreate -n lv01 -L 500M myvg

    The -n option allows the user to set the LV name to lv01. The -L option allows the user to set the size of LV in units of Mb in this example, but it is possible to use any other units. The LV type is linear by default, but the user can specify the desired type by using the --type option.

    Important

    The command will fail if the VG does not have a sufficient number of free physical extents for the requested size and type.

    For more information, see the lvcreate man page.