when you encounter the ORA-01031,you can deal with it by the steps.
cdccrs@node01 trace]$ sqlplus / as sysasm
SQL*Plus: Release 11.2.0.0.2 Beta on Sat Apr 14 22:15:47 2012
Copyright (c) 1982, 2012, Oracle. All rights reserved.
ERROR:
ORA-01031: insufficient privileges
Enter user-name: 1)export ORACLE_SID=+ASM1
2)export ORACLE_HOME=/u01/app/crshome
3)
[cdccrs@node01 trace]$ sqlplus / as sysasm
SQL*Plus: Release 11.2.0.0.2 Beta on Sat Apr 14 22:30:23 2012
Copyright (c) 1982, 2012, Oracle. All rights reserved.
Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.0.2 - 64bit Beta
With the Real Application Clusters and Automatic Storage Management options
SQL>