Failed to load media management library. Additional Information : 2

Hi All,

I am getting below error with RMAN.

Client : AIX

Netbackup : NetBackup-AIX53 7.1

Master server : SunOS 5.10 Generic_147440-01 sun4u sparc SUNW

Netbackup master server : NetBackup-Solaris10 7.1.0.3

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup command at 10/20/2014 07:25:11
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library
Additional information: 2

RMAN>

Recovery Manager complete.

Steps taken so far:

1. We have tried to relink the library.

2. Shutdown the DB and brought it online, relinked again.

3. Client machine was rebooted 80 days back.

Please let me know how to proceed further..

Note:The machine (client) acts as a media server as well.