RAC Installs: root.sh fails after installation on the first node

This post covers RAC Install failures: root.sh fails after installation on the first node


Excerpt from Problem Logs:
Disk Group GRID01 creation failed with the following message:
ORA-15018: diskgroup cannot be created
ORA-15017: diskgroup "GRID01" cannot be mounted
ORA-15003: diskgroup "GRID01" already mounted in another lock name space
Configuration of ASM ... failed

see asmca logs at /u01/app/grid/cfgtoollogs/asmca for details
Did not succssfully configure and start ASM at /u01/app/11.2.0/grid/crs/install/crsconfig_lib.pm line 6912.
/u01/app/11.2.0/grid/perl/bin/perl -I/u01/app/11.2.0/grid/perl/lib -I/u01/app/11.2.0/grid/crs/install /u01/app/11.2.0/grid/crs/install/rootcrs.pl execution failed


Cause: "This particular issue arises when root.sh is run concurrently on the first and other nodes on the RAC cluster. The correct approach is to run root.sh on the first node followed by the other nodes of the RAC cluster.\

Solution:
root.sh Fails on the First Node for 11gR2 Grid Infrastructure Installation (Doc ID 1191783.1)
Run the following as the root OS user on Node 1.
"$GRID_HOME/crs/install/rootcrs.pl -deconfig -force -verbose"
Followed by this command on the other nodes:
"$GRID_HOME/crs/install/rootcrs.pl -verbose -deconfig -force -lastnode"


How to Proceed from Failed 11gR2 Grid Infrastructure (CRS) Installation (Doc ID 942166.1)
Here is the master note for troubleshooting/fixing Grid Infrastructure Startup issues.
Troubleshoot Grid Infrastructure Startup Issues (Doc ID 1050908.1)