The amount of processing units of the CPU used to execute a task and how long it takes.

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19
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3answers
4k views

“Peaky” CPU Usage on Domain Controllers

We have two Windows Server 2008 SP2 (sadly not 2008 R2) Domain Controllers in a small 150 client domain that are exhibiting very "peaky" CPU usage. The Domain Controllers both exhibit the same ...
18
votes
2answers
2k views

How are CPU time and CPU usage the same?

In the Wikipedia page for CPU time, it says The CPU time is measured in clock ticks or seconds. Often, it is useful to measure CPU time as a percentage of the CPU's capacity, which is called ...
18
votes
2answers
2k views

Is there a Windows equivalent of Unix 'CPU steal time'?

In order to assess performance monitoring accuracy on virtualization platforms, the CPU steal time has become an increasingly relevant metric - see EC2 monitoring: the case of stolen CPU for an ...
16
votes
4answers
28k views

What does 'nice' mean on CPU utilization graphs?

On Ubuntu server load graphs I see 4 types of CPU consumption: User, System, Nice and Idle. What does Nice type mean?
15
votes
6answers
2k views

How often do you restart a heavily-utilized Windows Server 2008R2 Remote Desktop Server (VM)?

Note: I've read How Often Do Windows Servers Need to be Restarted? but this question pertains to our Remote Desktop server specifically. We have a Windows Server 2008R2 server - a VMware ESX VM - ...
12
votes
4answers
3k views

Why is 1 of my 24 CPUs Pegged at 100%?

I have an HP ProLiant DL380 G7 system using 2 6-core CPUs, with Hyper-threading enabled, for a total of 24 logical CPUs (as seen by Windows). When running our application, total system CPU ...
12
votes
11answers
8k views

What creates CPU I/O wait but no disk operations?

I have CPU I/O wait steady around 50%, but when I run iostat 1 it shows little to no disk activity. What causes wait without iops? NOTE: There no NFS or FUSE filesystems here, but it is using Xen ...
12
votes
4answers
8k views

What does %st mean in top?

Here is an example from my top: Cpu(s): 6.0%us, 3.0%sy, 0.0%ni, 78.7%id, 0.0%wa, 0.0%hi, 0.3%si, 12.0%st I am trying to figure out the significance of the %st field. I read that it means ...
12
votes
5answers
26k views

TrustedInstaller.exe takes a lot of CPU

Does anyone know how to fix issue with TrustedInstaller.exe when it takes a lot of CPU? Operating system: Windows 2008 x64 Windows' Modules Installer service is set to Manual.
11
votes
4answers
16k views

Linux CPU usage and Process Execution History

Is there any way to see what process(es) caused the most CPU usage? I have AMAZON EC2 Linux which CPU utilization reaches 100 percent and make me to reboot the system. I cannot even login through SSH ...
10
votes
7answers
3k views

High CPU utilization but low load average

We are running into a strange behavior where we see high CPU utilization but quite low load average. The behavior is best illustrated by the following graphs from our monitoring system. At about ...
10
votes
3answers
9k views

Is there a way to calculate the percentage CPU utilization by reading /proc/stat at once?

I guess the question is, could I somehow calculate the CPU utilization percentage just by reading the /proc/stat once? # head -1 /proc/stat cpu 67891300 39035 6949171 2849641614 118251644 365498 ...
10
votes
4answers
1k views

ps aux hanging on high cpu/IO with java processes

I'm having some issues with java process and nrpe checks. We have some processes that sometimes use 1000% cpu on a 32 core system. The system is pretty responsive until you do a ps aux or try to ...
10
votes
2answers
6k views

How to monitor CPU usage and performance on a Hyper-V server with several VM's

I have a server that is running Windows 2008 64 bit Hyper-V, with 8 gigs of RAM and Intel Xeon X3440 @ 2.53 Ghz, which gives me 8 logical cores in the performance monitor on the host system. I have ...
9
votes
3answers
5k views

Why is my router CPU at 40% when no processes use more than 2%?

I have a problem, I have a Cisco 1841 running Cisco IOS 15, and I get strange behavior. The CPU usage is shown as 40%, but there is no processes that is using this much CPU power. Here is an ...
9
votes
5answers
12k views

check history of cpu/memory usage in ubuntu?

Is there a way for me to review cpu or memory usage on my ubuntu linux server? I've noticed my server (lamp set up) being slow at times, but by the time I log in as root and run a PS command, ...
8
votes
3answers
9k views

Kill process with high CPU usage after X time? [closed]

running linux i have a few processes which tend to crash occasionally (game servers), which end up using 100% cpu. I'm looking for a program or script to check the cpu usage of a list of processes by ...
6
votes
3answers
2k views

When is sustained 100% CPU utilization not a worry?

Please help refine a discussion going on in our shop. Consider the following scenario. There is a Microsoft VPC running several apps and services (Windows 2003 server). The server has two or three ...
6
votes
5answers
2k views

SQL Server suddenly using only a small portion of CPU

We've got a Windows 2008 R2 server running SQL Server 2008. All of a sudden, the SQLServer process is refusing to go above 20% CPU usage. As of last week, when running a heavy query against the db it ...
6
votes
2answers
1k views

Prioritise ssh logins (nice)

Is there a preferred way to set "nice" for sshd? I need priority given to sshd such that I can login and easily fix stuff when something has gone wrong (eg DoS, badly behaved processes, etc)
6
votes
1answer
1k views

Very uneven CPU utilization with SQL Server 2012 on 2 processor computer with 16 cores / processor

After installing SQL Server Enterprise 2012 with the Server + Cal license model, on a computer with 2 processors each with 16 cores (and no hyperthreading involved) and putting the server under ...
5
votes
4answers
2k views

vCPU performance between 1 or 2 vCPU's

Within virtualisation (Predominantly VMware) is there a performance advantage using either 1 CPU with 4 cores or 2 CPU's with 2 cores? Let's assume the application running on a VM can use two CPU's.
5
votes
2answers
3k views

CPU allocation for VMs on ESXi

I'm a complete VMware know-nothing, but I recently set up 4 VMs on ESXi. 3 of the VMs are very non-resource-intensive (a lightly used file server, a lightly used domain domain controller, and a VMware ...
5
votes
3answers
7k views

Intermittent high CPU (100%) on production webserver

X-Post from StackOverflow: http://stackoverflow.com/questions/9465123/intermittent-high-cpu-100-on-production-webserver We have a web cluster with 3 web-servers, each with 24 cores & 24GB mem. ...
5
votes
4answers
2k views

Random high CPU usage on Linux using Apache

I've recently had a bit of a strange problem with my web server. Over the last day or so the site seems to be slowing down somewhat at random intervals, we don't seem to be experiencing any major ...
5
votes
4answers
4k views

Graphing per-user CPU usage on a Linux machine

I want to graph (graphical output would be great, i.e. a .png file) the following situation: I have users A, B, and C. I limit their resources so that when all users run a CPU intensive task at the ...
5
votes
2answers
4k views

Monitor and graph CPU usage per process and per thread

I need to monitor CPU usage by a given process and each of its threads. For each of them I want to have: average and maximum CPU usage percent, total CPU time used during the captured period, a ...
4
votes
4answers
2k views

CentOS - High CPU Usage at a particular time in the night

I have a CentOS-5 server that has very little load. A typical output of "sar" command shows like this: 02:20:01 PM CPU %user %nice %system %iowait %steal %idle 02:30:01 PM ...
4
votes
1answer
2k views

CPU% more than 100 in ps -aux

We use ps -aux to find out when tomcat process takes high CPU utilization, if that so we will send a alert to Group. But some times %CPU shows more than 100, but our application working fine. Is it ...
4
votes
2answers
605 views

Is EBS naturally CPU-hungry?

We have an m1.medium EC2 instance with a small (15G) EBS drive, running both Rails 3 and a PostgreSQL server. We've noticed CPU spikes at odd times, and finally realized that even simple, sustained ...
4
votes
1answer
740 views

How does a CPU ever go Idle enough to enter deeper C states?

Even if no user process is running, don't the kernel processes keep the CPU active enough so as to prevent it from entering a deeper C state like C1 or C2 ?
4
votes
1answer
7k views

How can a Perfmon “% Processor Time” counter be over 100%?

The counter, Process(sqlservr)\% Processor Time, is hovering around 300% on one of my database servers. This counter reflects the percent of total time SQL Server spent running on CPU (user mode + ...
4
votes
4answers
9k views

How can I investigate sustained high CPU usage by Microsoft.Exchange.Rpc.ClientAccess.Service.exe?

One CAS server in our array has nearly 90% of its 4 CPUs used. The remaining CAS servers are at 30 percent. How should I investigate what is causing this increase? Below is a graph of: Six ...
4
votes
1answer
6k views

Erratic CPU usage by mscorsvw.exe (.NET Runtime Optimisation Service)

I have a Server 2008 R2 Terminal Server that's just been kinda sitting around for the last three months with very, very low usage (perhaps 1 user for an hour, once a day). All of a sudden, for no ...
4
votes
5answers
13k views

Why is idle windows VM using so much CPU?

I have 2 VMs running as guests on a KVM virtualization platform running on Ubuntu 10.04. One VM is an Ubuntu 10.04 system, the other is a Windows 7 system. When both machines are completely logged ...
4
votes
2answers
4k views

WHM/CPANEL - High cpu and memory usage from Analog Stats [closed]

A single process is taking 100% of the cpu and 70% of the memory and starts every day on different account; /usr/local/cpanel/3rdparty/bin/analog +CIMAGEDIR /images/ +CDOMAINSFILE ...
4
votes
1answer
607 views

How is load average related to CPU utilization?

I am facing a load average of > 3 since past 2 days. The CPU utilization is never above 40 % in all cases. Here are some screenshots of Server Density monitoring tool that I use. The process ...
4
votes
4answers
3k views

Does WMI cause CPU Creep?

I have a few servers, running Server 2003 Std/Ent and SQL 2000/2005, that I've noticed will start showing higher CPU usages over time. Stopping the WMI service and restarting it will always bring it ...
4
votes
2answers
240 views

How to interpret values of Perfmon counter Hyper-V Hypervisor Virtual processor\CPU Wait time per dispatch

So there is a lot of guidance on the web that advises tracking the values of the Perfmon counter Hyper-V Hypervisor Virtual processor\CPU Wait time per dispatch as the nearest Hyper-V equivalent of ...
4
votes
1answer
727 views

Growing OS cache in RAM causing high system CPU usage

Long question, so please bare with me: I'm having a weird issue with a server that I've never seen before. On a machine with ~30G of RAM with an application that takes ~10G (spread across hundreds of ...
4
votes
1answer
206 views

Artificially Generate CPU Steal

Anyone know of a good way to artificially generate CPU steal? I have some automation I want to test which is triggered by CPU Steal, but for the life of me I can't figure out how to force CPU Steal ...
4
votes
1answer
3k views

Software Interrupts CPU time is high and keeps growing

My system is a Debian 6.0.3 x86_64 box w/kernel 2.6.32-5-openvz-amd64, it hosts a number of OpenVZ containers. I have recently migrated from LXC/newer kernel from backports repo to the stable OpenVZ ...
4
votes
1answer
801 views

Linux Cumulative User, System CPU Usage of Running Process?

On Linux (and other Unix-like OS's if there's a general answer), is there an easy way to get an output similar to the time command (current real time, user, and system CPU usage totals) for a process ...
4
votes
1answer
1k views

How to trace high CPU Apache process to particular virtualhost

Looking at the output of top I notice that intermittently there are one or two Apache processes consuming a high amount of CPU - anywhere between 50% - 90% The spikes in CPU usage come and go quite ...
4
votes
1answer
362 views

Memcached keeps increasing cpu ussage

I'm running a memcached server which is serving two front end servers. These are connecting to the memcached server from Apache2/PHP using the standard PECL library. For some reason the memcached on ...
4
votes
1answer
2k views

VMware - High CPU utilization on Windows 7 guest VM

I've just added some Windows 7 virtual machines to an existing VMWare vSphere 5.1 cluster. The hosts and vCenter are 5.1 with current updates via Update Manager. Looking at the vSphere client ...
4
votes
3answers
4k views

100% CPU when doing 4 or more concurrent requests with Magento

Currently I'm having trouble with a server running Magento, it's unbelievably slow. It's a VPS with a few Magento installations on it used for development, so I'm the only one using them. When I do 4 ...
4
votes
1answer
225 views

mongo and app server cpu

The beginning: We are using uwsgi and I decided to switch our configuration to use more workers/processes. Why: We have been seeing a traffic increase lately and in my tests with apache benchmark, ...
4
votes
2answers
405 views

Uneven CPU core utilization

tl;dr: First CPU core is consistently saturated, all other cores are consistently under-loaded. A VM, inside Ubuntu-based Xen XCP: $ uname -a Linux MYHOST 2.6.38-15-virtual #59-Ubuntu SMP Fri Apr ...
4
votes
4answers
3k views

IIS App Pool High CPU usage despite no requests

I have recently migrated a set of Windows Server 2008 R2 / IIS 7.5 servers to new servers running Windows Server 2012 / IIS 8. I am experiencing some odd behavior from IIS. We have 2 identical ...