Monthly Archives: October 2009

Understanding Unix/Linux Load Averages

October 7, 2009

I was looking at some linux server the other day, and was taking a look of the load averages using the “top” command.  After staring at the load averages for a while, I thought to myself ‘What does that mean exactly?” and “How do they get those numbers?”.  Well after some research I have found out that the load average is not a % of cpu usage, but is a representation of the load on the CPU by processes waiting for their time to use the CPU.

Below is a screenshot of the top command for reference.  Notice in the top right are the load averages “1.23″ 1.17″ “1.05″.  The first load average is for 1 minute, the middle is for 5 minutes, and the last one is for 15 minutes.

top and load averages

Now the important thing to remember about Unix/Linux load averages is that it is not a % of cpu usage, but how many processes are waiting to use the cpu.  The higher the load average, the more load the server in under.  Right about now you are probably wondering ” well what is a normal load average?” or “What is a high load average?”, the easiest way to determine if your load average is normal or high is to look at it in the following way:

CPU Cores Normal Load Average
1 1.00
2 2.00
3 3.00
4 4.00
8 8.00
16 16.00

As you can see a normal load average for a single core cpu is 1.00 while a dual core cpu can handle a load average of 2.00.  If it helps you out, you can think of 1.00 to be %100 for a single core and 2.00 be %100 for a dual core, and so on.

top showing each individual core (8 Cores)

Above is a screenshot of top showing each individual cores ultilization.  This is an 8 core cpu, so it’s normal load average is 8.00.  You can see this output in top by pressing “1″ on the keyboard.  Also, if you were wondering how I got top to display different colors, just press “z” on the keyboard.

The key thing to remember is that load averages in Unix/Linux are not % for cpu utilization, it is merely a representation of how many processes are waiting for their turn to use the processor.

References
http://www.linuxjournal.com/article/9001

http://blog.raamdev.com/2008/11/22/understanding-the-linux-load-averages

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By General Mills | Posted in Linux | Tagged , , , , | Comments (2)

Powershell built-in GUI Editor!!

October 5, 2009

Many of you have probably been on the look for a gui editor for the new windows powershell, well look no more!  Microsoft has included a built-in gui editor for powershell (I didn’t even know until now), and all you need to do to run it is follow one of the 2 ways below.

Method 1

1. Click Start
2. Type “Powershell ise” and hit enter
3.  The Powershell integrated scripting environment will then start!

Method 2

1.  Open powershell
2.  In the console type: “powershell_ise.exe”
3.  Hit enter.

Below are some screenshots for reference:

powershell - run ise

Below is a screenshot of what the Powershell ISE looks like.  Check it out!

powershell editor

The powershell gui editor basically works like this:  The top area is your script editor, the middle area is where you will see the output/results of your powershell script and commands.  The bottom area is where you can enter powershell commands as if you were on the powershell command prompt.

Once you start using it, I am sure you will see a increase in productivity while creating/testing scripts.  This is because it allows you to edit a script, run it, see it’s output, and even run commands as if you were at the command prompt.  It’s streamlined everything you could want or need into one program!  +1 point for Microsoft! (we’ll see how long that lasts lol).

Well what are you waiting for?  Lets get scripting!

Powershell Download Links

1.  Powershell 2.0 CTP

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By General Mills | Posted in Scripting, Windows | Tagged , , , , , , | Comments (0)