Removing a node from an active VCS cluster
In my previous article we discussed the steps need to add a new node into an existing VCS cluster (read more). In this article we perform the opposite by removing a node from the cluster.
This task can be performed only without interrupting the customer services. However you should make sure that you have sufficient resources to handle the load of the node being removed from the cluster.
For this example we will be removing vcsdevnod03 from the cluster
Stop VCS on the node
Top stop VCS on vcsdevnod03 we need to evacuate it, so that any service group running will switch over to the other nodes:
# haconfig -makerw # hasys -freeze -persistent vcsdevnod03 # haconf -dump # hastop -sys vcsdevnod03 -evacuate
Stop I/O fencing
Stop the VCS I/O fening on vcsdevnod03
# /sbin/vxfen-shutdown # vxfemadm -d
NOTE: Check status of fencing from vcsdevnod01 or vcsdevnod02
Stop LLT/GAB modules
Stop the LLT/GAB modules on vcsdevnod03:
# gabconfig -U # lltconfig -U
Remove VCS software
Remove the VCS software from vcsdevnod03 by running the installer utility and rename the main.cf file
Modify AutoStartList and SystemList
Run the following commands on vcsdevnod01 and vcsdevnod02 (assuming both nodes have vcsdevnod03 listed in their SystemList and AutoStartList attributes)
On vcsdevnod01
# hagrp -modify SG01 AutoStartList —delete vcsdevnod03 # hagrp -modify SG01 SystemList —delete vcsdevnod03
On vcsdevnod02
# hagrp -modify SG02 AutoStartList —delete vcsdevnod03 # hagrp -modify SG02 SystemList —delete vcsdevnod03
Remove node from ClusterServices SG
Remove vcsdevnod03 from ClusterServices SG on both vvsdevnod01 and vcsdevnod02
# hagrp -modify ClusterService AutoStartList -delete vcsdevnod03
Remove node from cluster
Now remove vcsdevnod03 from the cluster and sve the configuration (run this on vcsdevnod01 or vcsdevnod02)
# hasys -delete vcsdevnod03 # haconf -dump -makero