The error below is reported from backup team:
RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03009: failure of allocate command on t1 channel at 10/05/2016 10:48:48 ORA-19554: error allocating device, device type: SBT_TAPE, device name: ORA-27211: Failed to load Media Management Library
Rman backup fails at the begining of scrpit, when try allocate channels, It can looks a problem from the media but MML isn’t fault. The database has problem with memory, looked at diag directory there are trace files with warnings of run out of memory. Search in ML/MOS I found is a problem with memory. In this case I only get solved the problem after restart database. To resize PGA and SGA not work for me.
HTH – Antonio NAVARRO