Emre Baransel - Oracle Blog

This is the second post for the same error:

RMAN-00571: =======================================
RMAN-00569: ======= ERROR MESSAGE STACK FOLLOWS =======
RMAN-00571: =======================================
RMAN-03009: failure of allocate command on t1 channel at 08/03/2010 19:57:21
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library

First one was about lack of soft links under library directories.
http://emrebaransel.blogspot.com/2009/01/rman-03009-ora-19554-ora-27211.html

This one is about EMC networker misconfiguration.