ORA-19554: error allocating device, device type: SBT_TAPE, device name:

 run
{
allocate channel t1 type 'sbt_tape'
parms 'ENV=(TDPO_OPTFILE=/usr/tivoli/tsm/client/oracle/bin64/aml_monthly_tdpo.opt)';
restore controlfile from 'c-420538935-20140331-00';
alter database mount;
}2> 3> 4> 5> 6> 7>

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of allocate command on t1 channel at 04/06/2014 11:50:52
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library
Additional information: 2


Solution:
lrwxrwxrwx    1 root     system           19 Apr  6 11:53 libobk64.a -> /usr/lib/libobk64.a

ln -s $ORACLE_HOME/libobk64.a /usr/lib/libobk64.a