6.3. Specifying the Order Resources Should Start/Stop In

The way to specify the order in which resources should start is by creating rsc_order constraints.

Table 6.2. Properties of an Ordering Constraint

Field	Description
id	A unique name for the constraint
first	The name of a resource that must be started before the then resource is allowed to.
then	The name of a resource. This resource will start after the first resource.
score	If greater than zero, the constraint is mandatory. Otherwise it is only a suggestion. Default value: INFINITY
symmetrical	If true, which is the default, stop the resources in the reverse order. Default value: true

6.3.1. Mandatory Ordering

When the then resource cannot run without the first resource being active, one should use mandatory constraints. To specify a constraint is mandatory, use a scores greater than zero. This will ensure that the then resource will react when the first resource changes state.

If the first resource was running and is stopped, the then resource will also be stopped (if it is running)
If the first resource was not running and cannot be started, the then resource will be stopped (if it is running)
If the first resource is (re)started while the then resource is running, the then resource will be stopped and restarted