ORA-15477: cannot communicate with the volume driver

ORA-15477: cannot communicate with the volume driver
when add volume...

SQL> alter diskgroup data add volume 'asm_vol1' size 5G;
alter diskgroup data add volume 'asm_vol1' size 5G
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15477: cannot communicate with the volume driver

SQL> alter diskgroup data set attribute 'compatible.advm'='11.2';
alter diskgroup data set attribute 'compatible.advm'='11.2'
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15242: could not set attribute compatible.advm
ORA-15238: 11.2 is not a valid value for attribute compatible.advm
ORA-15477: cannot communicate with the volume driver

# acfsutil registry -l
acfsutil registry: CLSU-00100: Operating System function: open64 (/dev/ofsctl) failed with error data: 2
acfsutil registry: CLSU-00101: Operating System error message: No such file or directory
acfsutil registry: CLSU-00103: error location: OOF_1
acfsutil registry: ACFS-00502: Failed to communicate with the ACFS driver. Verify the ACFS driver has been loaded.

then load ACFS.

# /u01/app/grid/bin/acfsload start -s
ACFS-9327: Verifying ADVM/ACFS devices.
ACFS-9322: done.

Try again.

SQL> alter diskgroup data set attribute 'compatible.advm'='11.2';

Diskgroup altered.

SQL> alter diskgroup data add volume 'asm_vol1' size 5G;

Diskgroup altered.

SQL> !ls -l /dev/asm/asm_v*
brwxrwx--- 1 root oinstall 252, 86529 Mar 9 00:11 /dev/asm/asm_vol1-169