3.4. Configuring High Availability¶

High availability keeps virtual machines, containers, and iSCSI targets operational even if the hardware node they are hosted on fails. Three modes are available:

• DRS (default). In this mode, virtual machines and containers which were running on a failed node are relocated to healthy nodes based on available RAM and license capacity. This mode can be used for nodes on which the pdrs service is running.

• Round-robin (default fallback). In this mode, virtual machines, containers, and iSCSI targets from a failed node are relocated to healthy nodes in the round-robin manner.

• Spare. In this mode, virtual machines and containers from a failed node are relocated to a spare node—an empty node (that has no virtual machines, containers, iSCSI targets, and S3 clusters stored on it) with enough resources and a license to host all virtual environments from any given node in the cluster. Such a node is required for high availability to work in this mode.

For information on how to configure high availability and switch between its modes, consult Managing High Availability Clusters.