The status of the open entry point is passed as an argument to the next monitor entry point. The name of the argument is OpenStatus. The possible value for OpenStatus is 0 and 2. A value of 0 means that the open entry point completed successfully. A value of 2 means that the open entry point has timed out.

When an agent starts, the open entry point of each configured and enabled resource is called before its online, offline, or monitor entry points are called. This allows you to include initialization for specific resources. Most agents do not require this functionality and will not implement this entry point.

The open entry point is also called whenever the Enabled attribute for the resource changes from 0 to 1. The entry point receives the resource name and ArgList attribute values as input and returns no value.

A resource can be brought online, taken offline, and monitored only if it is managed by an agent. For an agent to manage a resource, the value of the resource's Enabled attribute must be set to 1. The open entry point creates the environment needed for other entry points to function. For example, the entry point could create files required by other entry points for the resource, or perform some resource-specific setup.