ServiceGroupHB Agent

Starts, stops, and monitors disk-based heartbeats associated with service groups. See the VERITAS Cluster Server 4.1 User's Guide for details.

The heartbeat region resides on a block device partition and consists of 128 blocks starting on the specified block number (see Disks attribute). The local system, via the ServiceGroupHB agent, tries to obtain "ownership" of the available disks as specified by the Disks' attribute. The system gains ownership of a disk when it determines that the disk is available and not owned by another system.

When the system's disk ownership meets the requirement of the AllOrNone attribute, it brings the resource online and monitors the resource. If the disk ownership falls below the AllOrNone requirement, VCS tries to fail over the group to another system.

Entry Points

• Online---Brings resource online after ownership of the required number of disks is obtained.
• Offline---Takes resource offline after relinquishing ownership of previously acquired disks.
• Clean---Takes resource offline and relinquishes ownership of previously acquired disks.
• Open---Creates logical disk objects based on Disks attribute at VCS startup.
• Close---At VCS shutdown, deletes the logical disk objects created by Open.
• Monitor---Periodically checks if local system has ownership of required number of disks.

State Definitions

• ONLINE---Indicates the system has the ownership of the logical disk objects.
• OFFLINE---Indicates that the system does not own the logical disk objects.
• UNKNOWN---Indicates that a problem exists either with the configuration or the ability to determine the status of the resource.