While I was installing RAC, the last step is to run root.sh, I did not wait for it to complete on the first node and then started to run on the second node, and messed up. I need to clean it up. use this oracle document as reference: https://support.oracle.com/epmos/faces/DocumentDisplay?_afrLoop=411427040358360&id=942166.1&_afrWindowMode=0&_adf.ctrl-state=c8ddpyf94_4 Step 1 : As root, run "$GRID_HOME/crs/install/rootcrs.pl -verbose -deconfig -force" on all nodes, except the last one. Step 2 : As root, run "$GRID_HOME/crs/install/rootcrs.pl -verbose -deconfig -force -lastnode" on last node. This command will zero out OCR, Voting Disk and the ASM diskgroup for OCR and Voting Disk Step 2 may not run sucessfully, but I can zero the OCR voting disk using dd command. # dd if=/dev/zero of=/dev/sdb1 bs=1024 count=100 Step 3 : As root, run $GRID_HOME/root.sh on first node Step 4 : As root, run $GRID_HOME/root.sh on all other node(s), except last