pre-stop script
    SHUTDOWN_LOG=/var/log/libvirt/qemu/shutdown_vms.log
    for RUNNING_VM in `virsh list | grep -E running | awk -F" " '{ print $2 }'`
    do
        echo "Shutting down ${RUNNING_VM} on `date`" >> $SHUTDOWN_LOG
        virsh shutdown ${RUNNING_VM}
    done
    echo -n "Waiting for VM's to shut down: " >> $SHUTDOWN_LOG
    for I in `seq 1 10`
    do
        RUNNING=`virsh list | grep running | wc -l`
        if [[ "$RUNNING" == "0" ]] 
        then 
            echo "done." >> $SHUTDOWN_LOG
            exit 0
        else 
            /bin/sleep 6 && echo -n " ${RUNNING} " >> $SHUTDOWN_LOG
        fi
    done
    echo " Cleaning up..." >> $SHUTDOWN_LOG
end script

我遇到的问题是,由于一些奇怪的原因,它永远不会回应“完成”.即使VM都正确关闭,它也会保持循环并因此停止60秒,或者它似乎完全忽略睡眠,将总数写入$SHUTDOWN_LOG并在我的VM同步到磁盘的过程中立即退出.

Shutting down FreeBSD-services on Mon Aug 22 02:07:42 MDT 2011
Shutting down FreeBSD-pgsql on Mon Aug 22 02:07:42 MDT 2011
Waiting for VM's to shut down:  1 [EOF]

是日志输出……有没有更好的方法从upstart登录？