Chapter 3. LVM Administration Overview

This chapter provides an overview of the administrative procedures you use to configure LVM logical volumes. This chapter is intended to provide a general understanding of the steps involved. For specific step-by-step examples of common LVM configuration procedures, see Chapter 5, LVM Configuration Examples.
For descriptions of the CLI commands you can use to perform LVM administration, see Chapter 4, LVM Administration with CLI Commands. Alternately, you can use the LVM GUI, which is described in Chapter 7, LVM Administration with the LVM GUI.

3.1. Creating LVM Volumes in a Cluster

In order to enable the LVM volumes you are creating in a cluster, the cluster infrastructure must be running and the cluster must be quorate. Creating clustered logical volumes also requires changes to the lvm.conf file for cluster-wide locking. Other than this setup, creating LVM logical volumes in a clustered environment is identical to creating LVM logical volumes on a single node. There is no difference in the LVM commands themselves, or in the LVM GUI interface.
In order to enable cluster-wide locking, you can run the lvmconf command, as follows: 
# /usr/sbin/lvmconf --enable-cluster
Running the lvmconf command modifies the lvm.conf file to specify the appropriate locking type for clustered volumes.

Note

Shared storage for use in Red Hat Cluster Suite requires that you be running the cluster logical volume manager daemon (clvmd) or the High Availability Logical Volume Management agents (HA-LVM). If you are not able to use either the clvmd daemon or HA-LVM for operational reasons or because you do not have the correct entitlements, you must not use single-instance LVM on the shared disk as this may result in data corruption. If you have any concerns please contact your Red Hat service representative.
For information on how to set up the cluster infrastructure, see Configuring and Managing a Red Hat Cluster.
For an example of creating a mirrored logical volume in a cluster, see Section 5.5, “Creating a Mirrored LVM Logical Volume in a Cluster”.