ORA-27211: Failed to load Media Management Library

RMAN backup failed With below error:

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of allocate command on ch1 channel at 06/20/2015 09:17:05
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library
Additional information: 4005

How to fix ORA-19554 and ORA-27211 errors?

CAUSE:

Before using RMAN with a media manager, media management software must be installed and configured on the target host or production network.

When allocating or configuring channels for RMAN to use to communicate with a media manager, specify the SBT_LIBRARY parameter to provide the path to the media management software library. When RMAN allocates channels to communicate with a media manager, it attempts to load the library indicated by the SBT_LIBRARY parameter.

If you do not provide a value for this parameter, RMAN looks in a platform-specific default location. On Linux/UNIX, the default library filename is $ORACLE_HOME/lib/libobk.so, with the extension name varying according to platform: .so, .sl, .a, and so on. On Windows the default library location is %ORACLE_HOME%binorasbt.dll.

If the database is unable to locate a media management library in the location specified by the SBT_LIBRARY parameter or the default location, then RMAN issues an ORA-27211 error and exits.

Resolving “Failed to load Media Management Library” Issue

Link libobk.so to your backup vendor supplied rman library using symbolic link.

Go to <ORACLE_HOME/lib/> directory.

$ pwd
/ora/app/oracle12c/product/12.1.0.2/dbhome_1/lib
$ cd  /usr/openv/netbackup/bin
$ ls -ltr libobk.so64
-r-xr-xr-x 1 root bin 1567895 Jun  20  2015 libobk.so64

$ cd /ora/app/oracle12c/product/12.1.0.2/dbhome_1/lib
$ ln -s /usr/openv/netbackup/bin/libobk.so64 libobk.so
$ ls -ltr libobk.so
lrwxrwxrwx 1 oracle dba 36 Jun 20 09:27 libobk.so -> /usr/openv/netbackup/bin/libobk.so64

Now start backup, if it gets completed successfully then no issues, if fail again then create below link in the same location as above.

$ ln -s /usr/openv/netbackup/bin/libobk.so64 libobk.a
$ ln -s /usr/openv/netbackup/bin/libobk.so64 libobk.so64
$ ls -lrt libobk*
lrwxrwxrwx 1 oracle dba 36 Jun 20 09:45 libobk.so -> /usr/openv/netbackup/bin/libobk.so64
lrwxrwxrwx 1 oracle dba 36 Jun 20 10:00 libobk.a -> /usr/openv/netbackup/bin/libobk.so64
lrwxrwxrwx 1 oracle dba 36 Jun 20 10:00 libobk.so64 -> /usr/openv/netbackup/bin/libobk.so64

For “ORA-19554: error allocating device, device type: SBT_TAPE” 
and “ORA-27211: Failed to load Media Management Library” you can get more info at: Backup and Recovery