XK0-005 · Question #792
A Linux administrator is troubleshooting poor CPU performance on a virtual machine. The administrator thinks that the underlying hypervisor may be starved for resources. The administrator uses the…
The correct answer is C. steal. When a virtual machine experiences CPU performance issues due to an overloaded hypervisor, the 'steal' CPU metric in top indicates the percentage of CPU time the VM wanted but could not get from the hypervisor. This metric is a key indicator of hypervisor resource contention…
Question
A Linux administrator is troubleshooting poor CPU performance on a virtual machine. The administrator thinks that the underlying hypervisor may be starved for resources. The administrator uses the top command to check the current CPU usage. Which of the following CPU metrics supports the administrator's theory?
Options
- Auser
- Bnice
- Csteal
- Dsystem
How the community answered
(31 responses)- A6% (2)
- B16% (5)
- C74% (23)
- D3% (1)
Why each option
When a virtual machine experiences CPU performance issues due to an overloaded hypervisor, the 'steal' CPU metric in `top` indicates the percentage of CPU time the VM wanted but could not get from the hypervisor. This metric is a key indicator of hypervisor resource contention impacting VM performance.
`user` CPU time represents the time spent executing user-space processes; it does not directly indicate hypervisor resource starvation.
`nice` CPU time is `user` CPU time spent on processes with a positive nice value (lower priority); it doesn't indicate hypervisor resource contention.
`steal` (st) CPU time, as reported by tools like `top` or `vmstat` inside a virtual machine, represents the time a virtual CPU was ready to run but could not due to the hypervisor servicing another virtual processor. A high `steal` value directly indicates that the underlying hypervisor is resource-constrained and cannot provide the requested CPU time to the VM, supporting the administrator's theory of hypervisor starvation.
`system` CPU time represents the time spent executing kernel-space code; it does not directly point to hypervisor resource limitations.
Concept tested: Linux CPU metrics, VM performance, hypervisor resource contention
Source: https://man7.org/linux/man-pages/man1/top.1.html
Topics
Community Discussion
No community discussion yet for this question.