A VSA cluster provides automatic failover from hardware and software failures.

Each VSA datastore has two volumes. A VSA cluster member exports the main volume as the VSA datastore. Another VSA cluster member maintains the second volume as a replica. If a failure occurs to the hardware, network equipment, or the VSA cluster member of the main volume, the main volume becomes unavailable, and the replica volume takes its place without service interruption. After you fix the failure and bring the failed VSA cluster member back online, the member synchronizes the main volume with the replica to provide failover in case of further failures.

A VSA cluster provides automatic failover from the following failures:

Single physical NIC failure

Single physical switch failure

Single physical host failure

Single VSA cluster member failure

The following illustration depicts automatic failover in a VSA cluster with 2 members. The replica volume takes over the failed main volume. In this case, to make sure that more than half of the members are online, the VSA cluster service simulates a VSA cluster member.

Failover in a VSA Cluster with 2 Members
Failover in a 2-member storage cluster

The following illustration depicts failover in a VSA cluster with 3 members.

Failover in a VSA Cluster with 3 Members
Failover in a 3-member storage cluster