Query on disabling/enabling cluster failover capabilities

[Former Member]

Hi

I am having one question regarding HA SAP systems in clustering environment (HP ServiceGuard) on HP-UX.

Is it possbile to disable / enable cluster failover capabilities without taking the resources (SAP & Oracle) offline / online i.e. is it possible to do this activity without stop/start of SAP.

Please suggest.

Thanks

Vinod

[Former Member]

Hi

You can enable and disable the automatic switch of a package with cmmodpkg -e <package> (-d to disable). You can verify the status with cmviecl. In my example SIDdbci is enabled and apSID01 is disabled:

host1:/root# cmviewcl

CLUSTER      STATUS       
SAPCL        up           

  NODE         STATUS       STATE        
  host1        up           running      
 
    PACKAGE      STATUS       STATE        AUTO_RUN     NODE         
    SIDdbci      up           running      enabled      host1     

  NODE         STATUS       STATE        
  host2        up           running      

    PACKAGE      STATUS       STATE        AUTO_RUN     NODE         
    apSID01      up           running      disabled     host2     

  NODE         STATUS       STATE        
  arbi         up           running     

This does not stop/switch anything, it just disables the automatic switchover.

Regards, Michael

[Former Member]

Hi Michael

Thanks for the details. Is it possible to take cluster offline or down without interfering running SAP.

Actually, I want to run Prepare tool for upgrade while SAP is not running in cluster mode such that the tool will not detect HA or cluster. Is this possible or the only option is to take SAP down and then disable the cluster & start Prepare tool.

Thanks

Vinod

[Former Member]

Hi

Theoretically it is possible to stop the cluster and manually start the SAP in a non-clustered mode. This would mean you have to activate the volume groups, mount the filesystems and startsap manually. The procedure is quite complicated and i strongly recommend you run the prepare in cluster mode. We upgraded a lot of systems and we never thought of disabling the cluster.

Best regards

Michael

[Former Member]

Hi Michael

Thanks for the valuable inputs. One more confusion I am having is that if we run Prepare in cluster mode the phase HIAV_CHK checks whether SAP system is a high availability system. If so, it asks to perform some additional actions manually.

But we are planning to perform actual upgrade in non cluster mode (i.e. after disabling the failover capabilities) using downtime minimized upgrade strategy. So, do we need to make any parameter changes in Prepare again before running actual upgrade (in non-cluster mode) or we shall continue with old prepare execution.

What all issues we can face while running Prepare in cluster mode and actual upgrade in non-cluster mode?

Please suggest.

Regards

Vinod