Book Image

CentOS High Availability

Book Image

CentOS High Availability

Overview of this book

Table of Contents (21 chapters)
CentOS High Availability
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Quorum disk


The second solution to the quorum problem in a two-node cluster configuration is to implement an additional quorum disk. A quorum disk is a shared storage block device both cluster nodes have access to. The Cluster and cluster nodes use this disk as cluster configuration storage and also as a secondary heartbeat communication channel. A quorum disk brings another vote to the cluster configuration, therefore eliminating the problem of a two-node cluster configuration quorum. A quorum disk can also be used as a secondary cluster heartbeat communication channel, and can therefore resolve cluster split-brain situations in the case of network communication failure.

With the quorum disk implemented, in the event of a cluster node failure quorum is reached by one cluster node vote and one quorum disk vote, and the cluster can continue to perform its normal operation.

Tip

The quorum disk solution is not reserved specifically for a two-node cluster configuration. It can be used as an additional...