create/update 'CPU Steal .md' file

CPU Steal .md

@@ -0,0 +1,20 @@
+#  CPU Steal
+
+CPU steal is the percentage of time that a virtual CPU has to wait for the physical CPU while the hypervisor is fulfilling processes from another virtual CPU. In short, CPU steal occurs when a shared CPU core is delayed in processing a request. This typically occurs when there is resource contention occurring, but that is not always the case.
+
+
+> My Linode's processes are not performing as expected. What can I do to see if CPU steal is occurring?
+> If you're noticing that your Linode's performance is suffering, there is a possibility that CPU steal is occurring. The best starting point to diagnose a potential CPU steal issue is to run the following commands.
+
+
+```shell
+iostat 10 10 && for x in `seq 1 1 30`; do ps -eo state,pid,cmd | grep "^D"; echo "-"; sleep 2; done && top -bn 1 | head -15
+```
+
+[explanation](https://www.linode.com/community/questions/18168/what-is-cpu-steal-and-how-does-it-affect-my-linode)
+
+---
+
+## Notes
+
+* `iostat` requires the `sysstat` package be installed on the host