Change/Remove node entries from OCFS2 config file

Step 1: Stop the cluster service 
#/etc/init.d/o2cb offline
#/etc/init.d/o2cb unload

Step 2: Edit the config file 

/etc/ocfs2/cluster.conf

Step 3: Start the cluster service
#/etc/init.d/o2cb load
#/etc/init.d/o2cb online

Source: https://oss.oracle.com/projects/ocfs2/dist/documentation/v1.2/ocfs2_faq.html#O2CB