One of my customers asked me recently, "whenever I boot one of my PowerHA AIX LPARs, cluster services always starts on boot. How can I stop this from happening?".

 

To prevent PowerHA from starting at boot, you can remove the /etc/inittab entry that is responsible for starting cluster services on boot.

 

# lsitab -a | grep hacmp6000

hacmp6000:2:wait:/usr/es/sbin/cluster/etc/rc.cluster -boot -i -b -A  # Bring up Cluster

 

# rmitab hacmp6000

 

How does that entry end up in /etc/inittab in the first place? Well, the most common reason is that an administrator started the cluster (smit clstart) and changed the "Start now, on system restart or both" option to either "restart" or "both" and pressed enter to start cluster services and make the change.

 

root@cgha1 / # smit clstart

                                  Start Cluster Services

 

Type or select values in entry fields.

Press Enter AFTER making all desired changes.

 

                                                     [Entry Fields]

* Start now, on system restart or both                both +

  Start Cluster Services on these nodes              [cgha1,cgha2] +

* Manage Resource Groups                              Automatically +

  BROADCAST message at startup?                       False +

  Startup Cluster Information Daemon?                 true

  Ignore verification errors?                         False +

  Automatically correct errors found during           Interactively +

  cluster start?

 

 

+--------------------------------------------------------------------------+

|                   Start now, on system restart or both                   |

|                                                                          |

| Move cursor to desired item and press Enter.                             |

|                                                                          |

|   now                                                                    |

|   restart                                                                |

|   both                                                                   |

                        

The output from the ‘smit clstart’ command will confirm that the entry has been placed in inittab.

 

Command: OK            stdout: yes           stderr: no

 

Before command completion, additional instructions may appear below.

 

Setting /etc/inittab to start PowerHA SystemMirror at system reboot for node(s): cgha1 cgha2
cgha1: Sep  4 2018 22:43:46Starting execution of /usr/es/sbin/cluster/etc/rc.cluster
cgha1: with parameters: -boot -R -i -C interactive -P cl_rc_cluster -A
cgha1:
cgha1: start_cluster: Starting PowerHA SystemMirror
cgha1: rc.cluster: Warning: You have selected to start cluster services during system
cgha1: boot time. Interactive correction of errors at system boot time cannot be
cgha1: honored. No error correction would be performed.
cgha1: Sep  4 2018 22:43:46usage: cl_echo messageid (default) messageSep  4 2018 22:43:46usage: cl_echo messageid (default) messageRETURN_CODE=0
cgha2: Sep  4 2018 22:43:47Starting execution of /usr/es/sbin/cluster/etc/rc.cluster
cgha2: with parameters: -boot -R -i -C interactive -P cl_rc_cluster -A
cgha2:
cgha2: start_cluster: Starting PowerHA SystemMirror
cgha2: rc.cluster: Warning: You have selected to start cluster services during system
cgha2: boot time. Interactive correction of errors at system boot time cannot be
cgha2: honored. No error correction would be performed.
cgha2: Sep  4 2018 22:43:47usage: cl_echo messageid (default) messageSep  4 2018 22:43:47usage: cl_echo messageid (default) messageRETURN_CODE=0

 

You can check if the inittab entry exists on all of your PowerHA nodes in a cluster, using the following command:

 

root@cgha1 / # clcmd lsitab -a | grep 6000

hacmp6000:2:wait:/usr/es/sbin/cluster/etc/rc.cluster -boot -i  -A   # Bring up Cluster

hacmp6000:2:wait:/usr/es/sbin/cluster/etc/rc.cluster -boot -i  -A   # Bring up Cluster

 

You can remove these entries, from all nodes in the cluster, with this command:

 

root@cgha1 / # clcmd rmitab hacmp6000

 

-------------------------------

NODE cgha2

-------------------------------

 

-------------------------------

NODE cgha1

-------------------------------

root@cgha1 / # clcmd lsitab -a | grep 6000

root@cgha1 / #

Tags:  starting /etc/inittab boot powerha inittab hacmp6000 chris at hacmp prevent gibson from aix