Networker异机恢复失败

大家好：

           环境是Networker7.6.1,NMO是5.0,OS:aix oracle.请大家帮忙！

异机恢复控制文件脚本是：

[toracle][/home/oracle]$cat restorezb.sh
run {
allocate channel ch1 type 'sbt_tape';
send 'NSR_ENV=(NSR_SERVER=backup,NSR_CLIENT=p730-02,NSR_RECOVER_POOL=Default)'; 
restore controlfile from 'con_c-4067959379-20120710-00';
release channel ch1;
}

报错是：

Starting restore at 10-JUL-12

channel ch1: restoring control file
released channel: ch1
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 07/10/2012 12:45:46
ORA-19870: error reading backup piece con_c-4067959379-20120710-00
ORA-27041: unable to open file
IBM AIX RISC System/6000 Error: 13: The file access permissions do not allow the specified action.
Additional information: 4