If clstat is not working, you may get the following error, when running clstat:

# clstat
Failed retrieving cluster information.

There are a number of possible causes:
clinfoES or snmpd subsystems are not active.
  snmp is unresponsive.
  snmp is not configured correctly.
  Cluster services are not active on any nodes.

  Refer to the HACMP Administration Guide for more information.
  Additional information for verifying the SNMP configuration on AIX 6
  can be found in /usr/es/sbin/cluster/README5.5.0.UPDATE

To resolve this, first of all, go ahead and read the README that is referred to. You'll find that you have to enable an entry in /etc/snmdv3.conf:

Commands clstat or cldump will not start if the internet MIB tree is not enabled in snmpdv3.conf file. This behavior is usually seen in AIX 6.1 onwards where this internet MIB entry was intentionally disabled as a security issue. This internet MIB entry is required to view/resolve risc6000clsmuxpd (1.3.6.1.4.1.2.3.1.2.1.5) MIB sub tree which is used by clstat or cldump functionality.

1. Enable the main internet MIB entry by adding this line in /etc/snmpdv3.conf file

    VACM_VIEW defaultView internet - included -

But doing so is not advisable as it unlocks the entire MIB tree

2. Enable only the MIB sub tree for risc6000clsmuxpd without enabling the main MIB tree by adding this line in /etc/snmpdv3.conf file

    VACM_VIEW defaultView 1.3.6.1.4.1.2.3.1.2.1.5 - included -

Note: After enabling the MIB entry above snmp daemon must be restarted with the following commands as shown below:

    # stopsrc -s snmpd # startsrc -s snmpd

After snmp is restarted leave the daemon running for about two minutes before attempting to start clstat or cldump.

Sometimes, even after doing this, clstat or cldump still don't work. The next thing may sound silly, but edit the /etc/snmpdv3.conf file, and take out the coments. Change this:

    smux 1.3.6.1.4.1.2.3.1.2.1.2 gated_password  # gated
    smux 1.3.6.1.4.1.2.3.1.2.1.5 clsmuxpd_password # HACMP/ES for AIX ...

To:

    smux 1.3.6.1.4.1.2.3.1.2.1.2 gated_password
    smux 1.3.6.1.4.1.2.3.1.2.1.5 clsmuxpd_password

Then, recycle the deamons on all cluster nodes. This can be done while the cluster is up and running:

    # stopsrc -s hostmibd
    # stopsrc -s snmpmibd
    # stopsrc -s aixmibd
    # stopsrc -s snmpd
    # sleep 4
    # chssys -s hostmibd -a "-c public"
    # chssys -s aixmibd  -a "-c public"
    # chssys -s snmpmibd  -a "-c public"
    # sleep 4
    # startsrc -s snmpd
    # startsrc -s aixmibd
    # startsrc -s snmpmibd
    # startsrc -s hostmibd
    # sleep 120
    # stopsrc -s clinfoES
    # startsrc -s clinfoES
    # sleep 120

Now, to verify that it works, run either clstat or cldump, or the following command:

  # snmpinfo -m dump -v -o /usr/es/sbin/cluster/hacmp.defs cluster 

Still not working at this point? Then run an Extended Verification and Synchronization:

  # smitty cm_ver_and_sync.select 

After that, clstat, cldump and snmpinfo should work.

powerhan2:/# lssrc -ls clstrmgrES |grep state

 Current state: ST_STABLE