Db2 High Availability Instance Configuration Utility (db2haicu) prerequisites

There is a set of tasks you must perform before using Db2® high availability instance configuration utility (db2haicu).

General

Before a database manager instance owner can run db2haicu, a user with root authority must run the preprpnode command. preprpnode is part of the Reliable Scalable Cluster Technology (RSCT) fileset for AIX® and the RSCT package for Linux®. preprpnode handles initializing the nodes for intracluster communication. The preprpnode command is run as a part of setting up the cluster. For more information about preprpnode, see preprpnode Command. For more information about RSCT, see Administering RSCT.

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Also, a user with root authority must disable the iTCO_wdt and iTCO_vendor_support modules.
  • On SUSE, add the following lines to the /etc/modprobe.d/blacklist file:
    alias iTCO_wdt off
alias iTCO_vendor_support off
  • On RHEL 5.x, add the following lines to the /etc/modprobe.conf file:
    blacklist iTCO_wdt
blacklist iTCO_vendor_support
  • On RHEL 6 and later releases, create the /etc/modprobe.d/iTCO_wdt.conf and /etc/modprobe.d/iTCO_vendor_support.conf files as follows:
    
[root@host1]# cat /etc/modprobe.d/iTCO_wdt.conf
blacklist iTCO_wdt
[root@host1]# cat /etc/modprobe.d/iTCO_vendor_support.conf
blacklist iTCO_vendor_support
You can verify that the modules are disabled by using the lsmod command.
Before running db2haicu, a database manager instance owner must perform the following tasks:
  • Synchronize services files on all machines that are being added to the cluster.
  • Run the db2profile script for the database manager instance that is being used to create the cluster domain.
  • Start the database manager using the db2start command.

For Linux, the GNU C library (glibc) version must be 2.4-31.109.1 or higher.

Db2 high availability disaster recovery (HADR)

If you will be using HADR functionality, perform the following tasks:

  • Ensure that both HADR databases exist on different systems.
  • Ensure all HADR databases are started in their respective primary and standby database roles, and that all HADR primary-standby database pairs are in peer state.
  • Ensure that you are using one of the following HADR synchronization modes: SYNC or NEARSYNC.
  • Configure hadr_peer_window for all HADR databases to a value of at least 120 seconds.
  • Disable the Db2 fault monitor.

Partitioned database environment

If configuring one or more database partitions for high availability, whether DPF HA or Mutual Failover HA with a shared disk, perform the following steps:

  • Configure the DB2_NUM_FAILOVER_NODES registry variable on all machines that are being added to the cluster domain.
  • Configure passwordless rsh or ssh, which is specified by DB2RSHCMD, for the Db2 instance user in the cluster. This applies to single-partition environments as well.
  • (Optional) Activate the database before running db2haicu.