crosscheck backup fails

@baan24

Hi all,RMAN crosscheck backup fails as foolows:

$ rman target sys/ catalog rmantest/@baan24

Recovery Manager: Release 10.2.0.4.0 - Production on Wed Dec 28 15:38:28 2011

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

target database Password:
connected to target database: BAAN (DBID=3830637121)
recovery catalog database Password:
connected to recovery catalog database

RMAN> crosscheck backup;

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of crosscheck command at 12/28/2011 15:38:47
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library
Additional information: 2


Rman configuration parameters:

RMAN> show all;

RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 1 DAYS;
CONFIGURE BACKUP OPTIMIZATION OFF; # default