aix自动更换磁带tapeutil

#!/usr/bin/ksh
ymd=`date +"%y%m%d"`
day=`date +"%w"`
dump_file="/backup/now.dmp"
echo "rename $dump_file to $ymd.dat"
mv /backup/now.dmp /backup/$ymd.dat
if [[ $? != 0 ]]
        then
        echo "File failed,Please check first."
        exit 1
fi
case "$day" in
        1 )
        echo "Starting mount tape#4096 to driver..."
        tapeutil -f /dev/rmt1 mount 4096
        if [[ $? = 0 ]]
        then
        echo "Starting Backup dumpfile to tape..."
        pax -x pax -wvf /dev/rmt1 /backup/$ymd.dat
                if [[ $? = 0 ]]
                then
                echo "Backup dump_file to tape has completed."
                pax -vf /dev/rmt1
                else
                echo "Backup dump_file to tape failed,Please check tape."
                fi
        else
        echo "Mount tape failed,please check it."
        exit 1
        fi
        tapeutil -f /dev/rmt1 unmount 4096
        echo "Remove dump_file $ymd.dat..."
        rm /backup/$ymd.dat
        ;;
        2 )
        echo "Starting mount tape#4097 to driver..."
        tapeutil -f /dev/rmt1 mount 4097
        if [[ $? = 0 ]]
        then
        echo "Starting Backup dumpfile to tape..."
        pax -x pax -wvf /dev/rmt1 /backup/$ymd.dat
                if [[ $? = 0 ]]
                then
                echo "Backup dump_file to tape has completed."
                pax -vf /dev/rmt1
                else
                echo "Backup dump_file to tape failed,Please check tape."
                fi
        else
        echo "Mount tape failed,please check it."
        exit 1
        fi
        tapeutil -f /dev/rmt1 unmount 4097
        echo "Remove dump_file $ymd.dat..."
        rm /backup/$ymd.dat
        ;;
        3 )
        .
        .
        .
        * )
        echo "Missioin Failed, Please contact administrator!"
        exit 1
        esac