启动探测程序

Monitor_start 方法获取 RT_basedir 属性的值，用来为 PROBE 程序构造完整的路径名。该方法通过使用 pmfadm 的无限重试选项（-n -1、-t -1）启动探测，意味着如果探测无法启动，PMF 将在无限时间期限内无限次地启动探测。

# Find where the probe program resides by obtaining the value of the
# RT_basedir property of the resource.
RT_BASEDIR=`scha_resource_get -O RT_basedir -R $RESOURCE_NAME -G \
$RESOURCEGROUP_NAME`

# Start the probe for the data service under PMF. Use the infinite retries
# option to start the probe. Pass the resource name, type, and group to the
# probe program. 
pmfadm -c $RESOURCE_NAME.monitor -n -1 -t -1 \
   $RT_BASEDIR/dns_probe -R $RESOURCE_NAME -G $RESOURCEGROUP_NAME \
   -T $RESOURCETYPE_NAME