HACMP
From Tecniq
HACMP 5.5, Rebranded to IBM PowerHA, Nov 2008, offers robust high availability and disaster recovery for IBM Power Systems, System p®, and System i® customers with mission-critical applications.
New features in V 5.5 include:
- Asynchronous replication support
- Updated support for DLPAR/CUOD to include support for IBM POWER5 and POWER6 processors
- Support for LPAR mobility to relocate critical applications
- PowerHA/XD PPRC support of Global Mirror when used with SAN Volume Controller
- Function to allow PowerHA/XD PPRC to support multiple storage subsystems at each site
- Better integration with the AIX operating system by avoiding modifications to the TC/IP bringing up process
HACMP/PowerHA Problems and resolutions
Here are a few solutions to certain situations we have encountered with HACMP.
Dilemma:
HACMP Sync problem. Cluster rhosts file correct on both nodes. Pinging between the two nodes is inconsistent - lots of missing packets.
Resolution - This could be due to the subnet masks being used for the aix boot address and the oracle vip which should be on, configured with the same subnet masks.
• Stop the cluster.
• Change the AIX subnet masks.
• Delete the default gateway and recreate with the correct mask.
• Change subnet mask in the HA IP network.
• Delete incorrect entries in the routing tables.
N.B If you encounter identical routes, and cannot delete them and you have checked ODM and they are not in there; Reboot node 1.
This removes the routes and pinging between the servers should now be consistent.
• Sync the cluster.
• Start cluster services on both nodes.
Situation: HACMP volume group changes - updating non-live node.
Resolution
On NODE 1
varyonvg -bu <volumegroup> (to unlock the vg for dual access!)
On NODE 2
importvg -L datavg hdisk6 (to import the changes to the VG onto node 2 ODM using a good disk from the vg)
On NODE 1
varyonvg datavg (to re-lock the volume group)
Disabling Cluster Verification.
The following is the process to deactivate Cluster Verification:
SMIT HACMP
Problem Determination Tools
HACMP Verification
Automatic Cluster Configuration Monitoring (set to disable)
