[Oracle RAC 11.2 Installation on Oracle Linux 5.8 x86_64]: Creating directory structure and assigning necessary permissions

Must be performed on each cluster node:

Quite an inconvenient directory layout, due to the fact that different directories require different permission sets. + when making changes, the installer may complain.

# mkdir -p /u01/app/oraInventory
# chown -R oracle11:oinstall /u01/app/oraInventory
# chmod -R 775 /u01/app/oraInventory

# mkdir -p /u01/app/grid/11.2
# chown -R oracle11:oinstall /u01/app/grid/11.2
# chmod -R 775 /u01/app/grid/11.2

# mkdir -p /u01/app/oracle/product/rac/11.2
# chown -R oracle11:oinstall /u01/app/oracle
# chmod -R 775 /u01/app/oracle