Novell BUSINESS CONTINUITY CLUSTERING 1.1 SP2 - ADMINISTRATION, Руководство администратора, Страница: 135 / 142

Setting Up Auto-Failover 135
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These conditions can be combined in any order to construct a more robust rule that helps to avoid an
undesired failover. For failover to occur, each condition of only one rule must be satisfied for the
specified cluster or clusters.
For rules with monitor conditions automatically created by using the Cluster Membership
Monitoring Settings table, you can add a condition that tests if the connection to the peer cluster is
up. Adding this condition changes the behavior of the rule. With this rule, a graceful automatic
failover of resources can happen when the connection to the peer cluster is up.
You can also specify or change the criteria for percent or number of nodes that are used to determine
if an automatic failover can occur.
IMPORTANT: Do not use a membership condition of total node failure (either 100 percent or the
total number of nodes); the condition cannot be satisfied because the cluster will not be up to report
this state.
If a cluster has been totally downed, you must bring up the master node in the downed cluster, then
run the
cluster resetresources
command on that node before you begin manually migrating
the BCC-enabled resources to peer clusters.
You should create a separate rule with a connection down condition. Adding a connection down
condition to an existing rule with a condition that tests cluster membership is not recommended. It is
highly unlikely that cluster membership information for a specific cluster will be reported to peer
clusters when the connection to that specific cluster is down.
For example, a rule might contain only one condition that tests whether a connection to a specific
cluster has been down for five or more minutes. Failover occurs when peer clusters agree that the
connection to the cluster specified in the rule has been down for five or more minutes. If the peer
clusters do not agree about the connection being down (that is, one cluster has a valid connection to
the specified cluster), failover does not occur. More complex rules can be constructed that contain
multiple conditions.
If previously configured, the fields under Failover Policy Configuration should already contain
information on the policies that were created in the Cluster Membership Monitoring Settings section
of the page.
1 Under Failover Policy Configuration , select a policy and click Edit to further refine a rule.
Click Delete to remove the rule, or click New to create a new rule that you can add the
additional failover conditions to.
2 Select the cluster that you want the rule to apply to, or select All to apply the policy to all
clusters.
3 Under Conditions , choose the type of condition and the appropriate values. To add multiple
conditions to the rule, click the Add button below the condition.
You can use the default setting of Monitor if you don't want to apply the cluster up or cluster
down criteria to this policy. You can also specify or change the percent or number of nodes
criteria that are used to determine if an auto failover can occur.
4 Click Apply to save your settings.