duplicate database to another host

hi all,

i m trying to duplicate database from one host to another using rman

this is the rman script

1. startup nomount auxiliary database

2. 

rman

connect target sys/password@PRIMARY

connect auxiliary /

run 

{

allocate auxiliary channel ch1 device type disk PARMS="SBT_LIBRARY=/opt/simpana/Base/libobk.so,BLKSIZE=262144,ENV=(CV_mmsApiVsn=2,CV_channelPar=ch1)"

allocate channel ch2 type 'sbt_tape' PARMS="SBT_LIBRARY=/opt/simpana/Base/libobk.so,BLKSIZE=262144,ENV=(CV_mmsApiVsn=2,CV_channelPar=ch2)"

duplicate target database to dupdb until time "to_date('Sep 02 2013 05:14:00','Mon DD YYYY HH24:MI:SS')"; 

release channel ch1;

release channel ch2;

} 

Oracle instance started