[grid@stage ~]$ sqlplus / as sysdba
SQL> ALTER DISKGROUP DATA ADD DISK 'ORCL:DATA_0001';
ALTER DISKGROUP DATA ADD DISK 'ORCL:DATA_0001'
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15260: permission denied on ASM disk group
Solution:
To perform this activities you need to connect to ASM instance as sysasm
[grid@stag ~]$ sqlplus / as sysasm
SQL> ALTER DISKGROUP DATA ADD DISK 'ORCL:DATA_0001';
Diskgroup altered.