错误再现：
[root@dg lib64]# /u01/app/11.2.0/grid/root.sh
Performing root user operation for Oracle 11g 


The following environment variables are set as:
    ORACLE_OWNER= grid
    ORACLE_HOME=  /u01/app/11.2.0/grid


Enter the full pathname of the local bin directory: [/usr/local/bin]: 
The contents of "dbhome" have not changed. No need to overwrite.
The contents of "oraenv" have not changed. No need to overwrite.
The contents of "coraenv" have not changed. No need to overwrite.


Entries will be added to the /etc/oratab file as needed by
Database Configuration Assistant when a database is created
Finished running generic part of root script.
Now product-specific root actions will be performed.
Using configuration parameter file: /u01/app/11.2.0/grid/crs/install/crsconfig_params
Improper Oracle Grid Infrastructure configuration found on this host
Deconfigure the existing cluster configuration before starting
to configure a new Grid Infrastructure 
run '/u01/app/11.2.0/grid/crs/install/roothas.pl -deconfig' 
to configure existing failed configuration and then rerun root.sh
/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/roothas.pl execution failed

解决办法：
[root@dg lib64]# /u01/app/11.2.0/grid/crs/install/roothas.pl -deconfig -force
Using configuration parameter file: /u01/app/11.2.0/grid/crs/install/crsconfig_params
CRS-4639: Could not contact Oracle High Availability Services
CRS-4000: Command Stop failed, or completed with errors.
CRS-4639: Could not contact Oracle High Availability Services
CRS-4000: Command Delete failed, or completed with errors.
CRS-4544: Unable to connect to OHAS
CRS-4000: Command Stop failed, or completed with errors.
ACFS-9313: No ADVM/ACFS installation detected.
Failure in execution (rc=-1, 0, No such file or directory) for command /etc/init.d/ohasd deinstall
Successfully deconfigured Oracle Restart stack
[root@dg lib64]# root.sh
-bash: root.sh: command not found
[root@dg lib64]# /u01/app/11.2.0/grid/root.sh
Performing root user operation for Oracle 11g 


The following environment variables are set as:
    ORACLE_OWNER= grid
    ORACLE_HOME=  /u01/app/11.2.0/grid


Enter the full pathname of the local bin directory: [/usr/local/bin]: 
The contents of "dbhome" have not changed. No need to overwrite.
The contents of "oraenv" have not changed. No need to overwrite.
The contents of "coraenv" have not changed. No need to overwrite.


Entries will be added to the /etc/oratab file as needed by
Database Configuration Assistant when a database is created
Finished running generic part of root script.
Now product-specific root actions will be performed.
Using configuration parameter file: /u01/app/11.2.0/grid/crs/install/crsconfig_params
LOCAL ADD MODE 
Creating OCR keys for user 'grid', privgrp 'oinstall'..
Operation successful.
LOCAL ONLY MODE 
Successfully accumulated necessary OCR keys.
Creating OCR keys for user 'root', privgrp 'root'..
Operation successful.
CRS-4664: Node dg successfully pinned.
Adding Clusterware entries to upstart


dg     2016/06/13 16:07:19     /u01/app/11.2.0/grid/cdata/dg/backup_20160613_160719.olr
Successfully configured Oracle Grid Infrastructure for a Standalone Server
[root@dg lib64]#