SFHA Solutions 6.0.1: About Veritas Cluster Server service groups
Veritas Cluster Server service groups are virtual containers that manage groups of resources required to run a managed application. You can create multiple service groups on a single node and they can function independently of each other. Moreover, you can also assign dependencies among the service groups depending on the complexity of your managed application.
For more information, see About service groups.
VCS supports three types of service groups:
- Failover service groups are configured for applications that do not support simultaneous access from multiple systems. A failover service group requires fewer resources but you must factor in some down time when the service group fails over to another node.
- Parallel service groups are configured if applications can run on multiple nodes without data corruption and also allow simultaneous access from multiple machines. A parallel service group is especially useful for high availability applications as there is no down time.
- A hybrid service group is for replicated data clusters and is a combination of the failover and parallel service groups. It behaves as a failover group within a system zone and as a parallel group across system zones. A hybrid service group cannot fail over across system zones. VCS allows a switch operation on a hybrid group only if both systems are within the same system zone. If no systems exist within a zone for failover, VCS calls the nofailover trigger on the lowest numbered node. Hybrid service groups adhere to the same rules governing group dependencies as do parallel groups.
For more information on failover service groups, parallel service groups, and hybrid service groups, see:
For more information on campus clusters, see Setting up campus clusters.
VCS components are configured using attributes. Attributes contain data about the cluster, systems, service groups, resources, resource types, agent, and heartbeats if you use global clusters. Moreover, the value assigned to the parallel attribute determines whether the service group is failover, parallel, or hybrid.
Administering service groups
You can administer service groups using the Java console, VCS command line interface, or Veritas Operations Manager (VOM). Symantec recommends using VOM to manage Cluster Server environments. The following are the links to the topics addressing administration of service groups using either method.
Administering service groups from Veritas Operations Manager (VOM)
To administer service groups from VOM, refer to Managing service groups.
Administering service groups from the command line
- Adding and deleting service groups
- Bringing service groups online
- Taking service groups offline
- Switching service groups
- Freezing and unfreezing service groups
- Enabling and disabling service groups
- Clearing faulted resources in a service group
- Flushing service groups
- Linking and unlinking service groups
Administering service groups from the Java Console
- Adding a service group
- Deleting a service group
- Bringing a service group online
- Taking a service group offline
- Switching a service group
- Freezing a service group
- Unfreezing a service group
- Enabling a service group
- Disabling a service group
- Autoenabling a service group
- Flushing a service group
- Linking service groups
- Unlinking service groups