8.2. Multi-State Resources: Resources That Have Multiple Modes
Multi-state resources are a specialization of Clone resources. They allow the instances to be in one of two operating modes; these are called
Master and Slave. The names of the modes do not have specific meanings, except for the limitation that when an instance is started, it must come up in the Slave state.
You can create a resource as a master/slave clone with the following single command.
pcs resource create resource_id standard:provider:type|type [resource options] \ --master [meta master_options]
The name of the master/slave clone will be
resource_id-master.
Alternately, you can create a master/slave resource from a previously-created resource or resource group with the following command: When you use this command, you can specify a name for the master/slave clone. If you do not specify a name, the name of the master/slave clone will be
resource_id-master or group_name-master.
pcs resource master master/slave_name resource_id|group_name [master_options]
For information on resource options, see Section 5.1, “Resource Creation”.
Table 8.2, “Properties of a Multi-State Resource” describes the options you can specify for a multi-state resource.
8.2.1. Monitoring Multi-State Resources
To add a monitoring operation for the master resource only, you can add an additional monitor operation to the resource. Note, however, that every monitor operation on a resource must have a different interval.
The following example configures a monitor operation with an interval of 11 seconds on the master resource for
ms_resource. This monitor operation is in addition to the default monitor operation with the default monitor interval of 10 seconds.
# pcs resource op add ms_resource interval=11s role=Master