转载自：http://blog.csdn.net/yui/article/details/6395033

译文（可能翻译得不是很流利，将就着看吧，实在看不懂了可以看下面的原文）

st 的全称是 Steal Time ，就是 Xen Hypervisor 分配给运行在其它虚拟机上的任务的实际 CPU 时间。

IBM 关于 steal time 的定义相当好：

%st(Steal time) 是当 hypervisor 服务另一个虚拟处理器的时候，虚拟 CPU 等待实际 CPU 的时间的百分比。

那么，这究竟是什么意思呢？

Steal 值比较高的话，你需要向主机供应商申请扩容虚拟机。服务器上的另一个虚拟机可能拥有更大更多的 CPU 时间片，你可能需要申请升级以与之竞争。另外，高 steal 值可能意味着主机供应商在服务器上过量地出售虚拟机。如果升级了虚拟机， steal 值还是不降的话，你应该寻找另一家服务供应商。

低 steal 值意味着你的应用程序在目前的虚拟机上运作良好。因为你的虚拟机不会经常地为了 CPU 时间与其它虚拟机激烈竞争，你的虚拟机会更快地响应。这一点也暗示了，你的主机供应商没有过量地出售虚拟服务，绝对是一件好事情。

原文及原文地址： http://www.91linux.com/html/article/cmd/top/20090417/16525.html

st, It turns out that this stands for 'Steal Time' and is the amount of real cpu that the Xen Hypervisor has allocated to tasks other than running your Virtual Machine.

IBM's definition of steal time is actually pretty good:

Steal time is the percentage of time a virtual CPU waits for a real CPU while the hypervisor is servicing another virtual processor.

So, relatively speaking, what does this mean?

A high steal percentage may mean that you may be outgrowing your virtual machine with your hosting company. Other virtual machines may have a larger slice of the CPU’s time and you may need to ask for an upgrade in order to compete. Also, a high steal percentage may mean that your hosting company is overselling virtual machines on your particular server. If you upgrade your virtual machine and your steal percentage doesn’t drop, you may want to seek another provider.