Repairing the cluster manager domain

If a failure situation occurs with a Db2® pureScale® instance which requires the cluster manager domain to be re-created, use the db2cluster command to re-create it.

Before you begin

Important: To run the db2cm utility as the root user, ensure the DB2INSTANCE environment variable is set to the instance owner.

The Db2 instance must be stopped before performing this task; all nodes in the cluster must be online.

About this task

Using the db2cluster command will re-create the domain with the same topology and configuration as the existing domain (such as the cluster services tiebreaker, host failure detection time).


Restrictions

The command used in this task can only be run as the Db2 cluster services administrator.

Procedure

  1. Use the DB2INSTANCE environment variable to specify the target instance. 
    export DB2INSTANCE=<inst-name>
  2. Issue the db2cluster command with the -repair -domain option while inside the install directory or the sqllib/bin directory. 
    db2cluster -cm -repair -domain <domain-name>
    To obtain the CM domain name, run the db2cluster command: db2cluster -cm -list -domain. (You can also obtain the domain name with the db2greg -dump command.)

    If the cluster manager domain is in an unhealthy state or if there are resources still online, the db2cluster command may fail and indicate that the command should be re-issued with the -force option. Re-issuing the command with the -force option will successfully re-create the cluster manager domain in these cases, but it will also reset the cluster host failure detection time to the default value of 8 seconds. The host failure detection time can be subsequently re-adjusted in this case.

Results

After successful re-creation of the cluster manager domain, bring the instance back online using the db2start command.

If the cluster manager domain cannot be successfully re-created, contact an IBM Service Representative for more information about how to recover from this problem. You might be asked to provide the original cluster manager configuration information, which db2cluster saves to a text file (/tmp/ibm.db2.db2cluster_cm_repar_domain_config_<TIMESTAMP>) before it tears down the cluster manager domain.

Example

A DBA with Db2 cluster services authority needs to re-create a cluster manager domain, MYDOMAIN, in Db2 instance MYINST. 
export DB2INSTANCE=myinst1
db2cluster -cm -repair -domain mydomain
As the domain is torn down and re-created, db2cluster issues informational messages about the progress and the successful completion of the operation:
 Deleting the domain 'mydomain' from the cluster ...
 Deleting the domain 'mydomain' from the cluster was successful.
 Creating domain 'mydomain' in the cluster ...
 Creating domain 'mydomain' in the cluster was successful.
 Configuring quorum device for domain 'mydomain' ...
 Configuring quorum device for domain 'mydomain' was successful.
 The host failure detection time has been set to 8 seconds.
 The resource model for the instance 'myinst1' has been re-created.
 The cluster manager domain has been successfully repaired.