25.8.1 Groups and resources

The unit VERITAS Cluster Server uses for switching systems between nodes is called a group. The applications comprising a group operate using what are referred to as resources. The following types of resources are available:

Organization of this subsection
(1) Setting up groups and resources
(2) Defining the parent-child relationships of resources
(3) Dummy file (applicable to the monitor mode only)
(4) Notes

(1) Setting up groups and resources

Provide NICs, logical IP addresses, and a shared disk, and set them up as VERITAS Cluster Server resources to form a group. In the explanation in this manual, VERITAS Volume Manager is used for setting up a shared disk. When these resources are set up, resource types that have already been defined (such as NIC type, IP type, and DiskGroup) can be used.

It is also necessary to set up HiRDB as a resource within the group so that it can be managed by VERITAS Cluster Server. For this purpose, a new resource type is defined for HiRDB. For details on how to define a resource type, see 25.8.2 HiRDB resource type definition.

The resource type name is HiRDB_S in the case of a HiRDB/Single Server and HiRDB_P in the case of a HiRDB/Parallel Server. This manual uses the generic notation HiRDB_x for resource type names; substitute HiRDB_S or HiRDB_P as appropriate.

(2) Defining the parent-child relationships of resources

Parent-child relationships are defined for the resources defined within a group. For HiRDB to run, logical IP addresses (when IP addresses are inherited) and the shared disk must be enabled. Therefore, HiRDB_x type resources must be defined as parent resources to the IP type and DiskGroup type resources. Figure 25-50 shows a group configuration.

Figure 25-50 Group configuration

[Figure]

(3) Dummy file (applicable to the monitor mode only)

If HiRDB terminates abnormally when operating the system switchover facility in the monitor mode, HiRDB will restart. For this reason, it is not necessary to monitor the operating status of HiRDB. However, you must create a dummy file for notifying VERITAS Cluster Server that HiRDB is currently active as a resource. This dummy file must satisfy all the conditions listed below.

Conditions
  • Dummy file is created when HiRDB is started by VERITAS Cluster Server.
  • Dummy file is deleted when HiRDB is terminated by VERITAS Cluster Server.
  • While dummy file is in existence, the HiRDB resource is considered to be running.
    Hint
    If the dummy file is deleted inadvertently, VERITAS Cluster Server assumes that an error has occurred in the resource and switches systems. To prevent this, specify Critical=0 as the resource attribute value for the HiRDB_x type resource. Also, to prevent the dummy file from being deleted inadvertently, create it using the name $PDDIR/.pdveritas.

(4) Notes