ASM Diskgroup Mount Fails With ORA-15032 And ORA-15260

When you try to mount the ASM disk group you get the following errors:

SQL> select name, total_mb from v$asm_diskgroup_stat;

NAME              TOTAL_MB
-------               --------
DATA_DG       4096
FRA_DG          0

SQL> alter diskgroup FRA_DG mount;

alter diskgroup FRA_DG mount;
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15260: permission denied on ASM disk group


Solution:
This error is caused by a new role was introduced in 11g if you logged in as SYSDBA and trying to mount the disk group, you may encounter this error.

And you need to login as SYSASM to mount this diskgroup correctly.

SQL> connect / as SYSASM

SQL> alter diskgroup FRA_DG mount;
Diskgroup altered.