"If you want to use sdb after the next reboot, you should change the following entry:
node.conn[0].startup = manual to automatic
in the /etc/iscsi/nodes/<iscsi target name>/<ip address> file. After you change it the iSCSI daemon will login to this target."

For those who try this Howto on a OpenSUSE 10.2 server:

I also needed to add a "sleep 30" instruction   to function iscsi_login_all_nodes() in order to successfully log in to the target.
this function can be found in the /etc/init.d/open-iscsi script and, after this addition should look like:

iscsi_login_all_nodes()
{
    sleep 30
    $ISCSIADM -m node 2> /dev/null | while read line; do
        set ${line}
        TARGET=$(echo $line | cut -d" " -f2)
        PORTAL=$(echo $line | cut -d"," -f1)
        STARTUP=`$ISCSIADM -m node --targetname $TARGET -p $PORTAL | grep "node.conn\[0\].startup" | cut -d' ' -f3`
        NODE=`$ISCSIADM -m node --targetname $TARGET -p $PORTAL | grep "node.name" | cut -d' ' -f3`
        if [ $STARTUP = "automatic" ] ; then
            echo -n "Logging into $NODE: "
            $ISCSIADM -m node --targetname $TARGET -p $PORTAL -l
            rc_status -v
        fi
    done
}