Failed to load Media Management Library

Error

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of allocate command on c1 channel at 06/26/2018 11:28:08
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library

Additional information: 2

Cause

Link between Oracle database server software and NetBackup API library wasn't found.

$ ls -l $ORACLE_HOME/lib/libobk.so
/u01/app/oradr/product/12.1.0.2/dbhome_1/lib/libobk.so: No such file or directory

Solution

Create soft link between Oracle database server software and NetBackup API library

$ ln -s /usr/openv/netbackup/bin/libobk.so64.1 $ORACLE_HOME/lib/libobk.so

$ ls -l $ORACLE_HOME/lib/libobk.so
lrwxrwxrwx   1 oradr    oinstall      38 Jun 26 11:30 /u01/app/oradr/product/12.1.0.2/dbhome_1/lib/libobk.so -> /usr/openv/netbackup/bin/libobk.so64.1
$