Novell LINUX ENTERPRISE 11 - HIGH AVAILABILITY, Manual, Page: 53 / 298

For more information on configuring constraints and detailed background information
about the basic concepts of ordering and collocation, refer to the following documents
available at
http://clusterlabs.org/wiki/Documentation
:
• Configuration 1.0 Explained , chapter Resource Constraints
• Collocation Explained
• Ordering Explained
4.5 Specifying Resource Failover
Nodes
A resource will be automatically restarted if it fails. If that cannot be achieved on the
current node, or it fails N times on the current node, it will try to fail over to another
node. You can define a number of failures for resources (a
migration-threshold
),
after which they will migrate to a new node. If you have more than two nodes in your
cluster, the node a particular resource fails over to is chosen by the High Availability
software.
If you want to choose which node a resource will fail over to, you must do the following:
1
Configure a location constraint for that resource as described in Procedure 4.4,
“Adding or Modifying Locational Constraints” (page 39).
2
Add the
migration-threshold
meta attribute to that resource as described
in Procedure 4.2, “Adding or Modifying Meta and Instance Attributes” (page 36)
and enter a Value for the migration-threshold. The value should be positive and
less that INFINITY.
3 If you want to automatically expire the failcount for a resource, add the
failure-timeout
meta attribute to that resource as described in Proce-
dure 4.2, “Adding or Modifying Meta and Instance Attributes” (page 36) and
enter a Value for the failure-timeout.
4
If you want to specify additional failover nodes with preferences for a resource,
create additional location constraints.
Configuring Cluster Resources with the GUI 43