VMware Tools version number higher than expected

Today, when performing a VMware Health Check, I came across a strange issue with a customer of mine. Well, issue is maybe a big word, but I discovered the VMware Tools version some of the VMs had running, were newer than the VMware Tools version from a newly installed VM. To make sure I double checked by removing the VMware Tools and reinstalling them, again the VMware Tools version was less than the tools version of the suspicious VMs.

The VMs with the very high VMware Tools version had version 8448 running. When checking the VMware Tools about page, it showed:  8.8.0 build 471268. The other ‘normal’ VMs had VMware Tools version 8300. The Windows VMware Tools about page showed 8.3.12 build 493255. The vSphere environment I was running this on had vCenter 4.1 and ESXi 4.1 update 2 build 502767. [Read more...]

Powershell: TimeSync in VMs and Windows w32time service settings

Customer of mine never heard about potential time sync problems in a virtual environment and when checking a number of VMs, I learned that they clearly had no default configuration for TimeSync in the VMware Tools. I decided to write a Powershell script that will list the VMware Tools setting for time sync and for Windows systems it will try to find the settings for the w32time service. The output will look like this:

Name TimeSync StartMode State OS
srv01 True Auto Running Microsoft Windows Vista (32-bit)
srv02 True Disabled Stopped Microsoft Windows XP Professional (32-bit)
srv03 False Auto Running Microsoft Windows XP Professional (32-bit)
srv04 False Unknown Unknown Red Hat Linux
srv05 True Unknown Unknown Suse Linux (32-bit)
srv06 True Disabled Stopped Microsoft Windows Server 2003, Standard Edition (32-bit)

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Memory overcommit in production? YES YES YES

There was a good discussion on twitter on memory overcommit and the value of memory overcommit and whether you should or should not use it in production. What struck me in this was that on a subject like this, there is so much misunderstanding although there is a lot of documentation available that can explain the subtle difference between good and bad overcommit of memory.

Memory overcommit, the basics.

In short: When you assign more RAM to your VMs than available in your host.

Good memory overcommit: When you assign more RAM to your VMs than available in your host BUT never cross the line where the amount of RAM that is USED by your VMs is more than available in your host.

Bad memory overcommit: When you assign more RAM to your VMs than available in your host AND cross the line where the amount of RAM that is USED by your VMs is more than available in your host.

[Read more...]