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NetWorker: ORA-27211: Failed to load Media Management Library Error

Summary: Oracle Backup and Restore with NMDA fails with error: Failed to load the Media Management Library.

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Instructions

Symptoms:

Oracle Backup and Restore with NMDA fails with error:  
RMAN-00571: =========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: Failure of allocate command on CH1 channel at 10/19/2012 01:37:21
ORA-19554: Error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library.


Cause:

This error message is related to Oracle not being able to successfully load the media manager layer, in this case, the NMDA Oracle library.


Resolution:

You must verify a couple of things in order to resolve this issue:

  • Ensure that you have the correct bit number as the Oracle server. That is, if Oracle is 32-bit, you must have the 32-bit version of NMDA. If Oracle is 64-bit, you must have the 64-bit version of NMDA.
  • Confirm that as per part of the install process, you have correctly linked NMDA with Oracle. This is seen in the NMDA install guide. See the NMDA install guide for all the latest installation notes. 
As an example of Linux, it looks like the following:
Log in as the $ORACLE_HOME owner, for example user "oracle"  
cd $ORACLE_HOME/lib
ln -s /usr/lib/libnsrora.so libobk.so
 
The Oracle file libobk.so should map to the NMDA library once the symlink is correctly created.
Example: 
[oracle@ora1 ~]$ cd $ORACLE_HOME/lib
[oracle@ora1 lib]$ ls -las libobk*
0 lrwxrwxrwx. 1 oracle oinstall 21 Sep 22 09:46 libobk.so -> /usr/lib/libnsrora.so

The extension on the libobk and libnsrora files varies based on the OS.
  • On HP PA-RISC, the files are libobk.sl and /usr/lib/libnsrora.sl.
  • On AIX, the files are libobk.a and /usr/lib/libnsrora.a.
For Windows Oracle platforms:
The Media Management Library for Oracle is not called libnsrora, instead it is called orasbt.dll, and is located in <NetWorker installation Directory>\nsr\bin.

You must ensure that the system PATH variable of the OS lists the NetWorker installation directory ahead of all others. For example, C:\Program Files\EMC NetWorker\nsr\bin should be listed first.  

The NetWorker client directory pathname may include spaces. Do not include any spaces before or after the NetWorker client directory pathname in the system PATH environment variable. If there are any spaces before or after the pathname in the variable, the Oracle software cannot locate the NMDA library file orasbt.dll during backup and restore operations.

If you installed the NetWorker client software for the first time in a particular directory on an Oracle server, copy orasbt.dll file from the <NetWorker installation Directory>\nsr\bin to the windows\system32\ directory, and copy the nsrsbtcn.exe file from the <NetWorker installation Directory>\nsr\bin to the windows\system32\ directory.

Then restart the Oracle server instance.

For Oracle RAC, you must do all the above on all the nodes in the RAC cluster.


Alternative:

If the above resolution did not link the library, manually add the following line to the RMAN script,

"SBT_LIBRARY=/usr/lib/libnsrora.so" or "SBT_LIBRARY=<NetWorker installation Directory>\nsr\bin\orasbt.dll"; 

Example:

run{
allocate channel t1 type 'sbt_tape' PARMS='SBT_LIBRARY=/usr/lib/libnsrora.so SBT_PARMS=(NSR_SERVER=linux1.amer.lan,NSR_CLIENT=ora.amer.lan,NSR_DATA_VOLUME_POOL=ddveamerlan)';
......
......
}

Affected Products

NetWorker, NetWorker Module for Databases and Applications
Article Properties
Article Number: 000196088
Article Type: How To
Last Modified: 06 Oct 2025
Version:  5
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