A. Mikkelsen VMware ESX scripts, commands, tools and other nice to know things that will make your virtualization days easier!!!!

Wednesday, September 29, 2010

Configure IBM Blades (running ESX) and Cisco switches for failover

Filed under: Performance,Troubleshooting,White Papers — Tags: , , , , , , , , , , — A. Mikkelsen @ 21:18 pm

Using IBM Blades and Cisco switches to run your ESX enviroment?

If yes, have you tested what happens if you unplug the network cables going into one switch?

If you like me have bundled 2 or more cables going from one switch, to one backbone switch and done the same for the other switch, then your VM’s using that switch will loose network connection (from outside the host).
This is not the way I wanted the setup to work.

After a bit of googling i found a blog from Scott Lowe (http://blog.scottlowe.org/2007/06/22/link-state-tracking-in-blade-deployments/) about the problem and also a solution.
The solution is called Link State Tracking. Many users have tried the solution and have got it to work, so I had to test it…..

I added the following lines to each of the Blade Switches (Port-Channel, group and interfaces may be different on your system).

----------UPLINK to CORE switch------------
interface Port-Channel1
link state group 1 upstream

----------LINK to Blade server------------
interface range GigabitEthernet0/1 - 14
link state group 1 downstream

----------Global command------------
link state track 1

conf t
interface Port-Channel1
link state group 1 upstream
interface range GigabitEthernet0/1 - 14
link state group 1 downstream
link state track 1

Remember to write the changes to memory using


After this was done on both Blade switches, i just had to test it.
I started a ping to a VM that I knew was using Switch1 to communicate with external network traffic.
Then I unplugged the to 2 network cables going into Switch1 and waited to see if the ping command would loose the communication with the VM….
It didn’t loose connection. So the the VM must have switched to Switch2.

So configuring the Blade Switches for Link State Tracking is to proper way to configure the switches.
A big thanks goes to Scott Lowe for the blog on Link State Tracking.

Wednesday, January 6, 2010

Interpret the output of ESXTOP in vSphere

Filed under: Performance,Troubleshooting,vSphere (ESX) — Tags: , , , , — A. Mikkelsen @ 9:39 am

If you need a good guide to Interpreting the statistic from ESXTOP then take a look at this guide from VMware.


I’m using it to troubleshoot performance issues (poor response times) from clients in different locations, when using the remote console.

Tuesday, April 28, 2009

VMKUSAGE is back… Can you belive it…..

Filed under: Performance,Tools,Virtual Center — Tags: , , , , , — A. Mikkelsen @ 21:17 pm

VMware have included the old and trustworthy performance monitor VMKUSAGE in VC 2.5 U4.
This time the monotor has been added to VC as a plugin.

To get access to the new plugin you have to follow this knowledge base article.

If you like me upgraded your VC without stopping the Webaccess service first you have to follow this KB article before the plugin will work.

See more screenshots at www.run-virtual.com.

Wednesday, July 9, 2008

Quick guide to tweak a VM for better performance

Filed under: ESXi,Performance,Tools,vSphere (ESX),White Papers,Workstation — A. Mikkelsen @ 18:39 pm

Today i came accoss this handy little guide to boost performance of a VM.

  1. Disable the pre-logon screensaver:
    Open Regedit
    HKEY_USERS\.DEFAULT\Control Panel\Desktop
    Change the value of “ScreenSaveActive” to 0.
  2. Disable updates of the last access time attribute for your NTFS filesystem, especially for i/o intensive vm’s this is a real boost:
    Open CMD
    fsutil behavior set disablelastaccess 1
  3. Disable all visual effects:
    Properties on your desktop
    Appearance -> Effects
    Disable all options.
  4. Disable mouse pointer shadow:
    Control Panel -> Mouse
    Click on the tab “pointers” and switch “enable pointer shadow” off.

A big thanks goes to Yellow Bricks – Read the full guide here

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