Category Archives: Books

VMware vSphere PowerCLI Reference – Book

By | September 4, 2011

If you haven’t read or read about the must have PowerCLI book “VMware vSphere PowerCLI Reference: Automating vSphere Administration“, by Luc Dekens, Alan Renouf, Glen Sizemore, Arnim van Lieshout and Jonathan Medd, then you need to check it out. The book will show you how to automate your VMware infrastructure from vCenter to VM’s. Automate… Read More »

Downgrading ESX virtual hardware 7 to 4

By | November 19, 2010

When you upgrade your vSphere environment you normally also upgrade the VM’s virtual hardware to version 7, to take advantage of the new features. This is pretty normal procedure for all VMware admins. But in some very very rare cases you might need to move a VM upgraded to hardware version 7, to a host… Read More »

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

By | September 29, 2010

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… Read More »

Extend disk with snapshots – How to fix the error

By | October 29, 2009

Yesterday I by mistake extended a disk on a VM that had snapshots. Using vmkfstools. Kind of like this thread ( This resulted in the following PowerOn error: Failed to power on Servername on Host in Cluster: Cannot open the disk ‘/vmfs/volumes/LUN/Folder/VM.vmdk’ Reason: The parent virtual machine disk has been modified since the child was… Read More »

Partitioning you ESX host (vSphere)

By | October 6, 2009

Duncan Epping has released a great post on how to partition your ESX 4.0 (vSphere) using scripting and the grafical installer You cannot define the sizes of the /boot, vmkcore, and /vmfs partitions when you use the graphical or text installation modes. You can define these partition sizes when you do a scripted installation.… Read More »

Black screen in a Windows VM or an a physical server

By | September 10, 2009

Over the past few months we have seen a few Windows servers with a black screen. Meaning You can’t see the logon promt You get a black screen when you connect with RDP We found that the problem was caused by a change in the Windows color scheme. The solution is to copy the color… Read More »

Sudden error – kernel Panic…..

By | March 19, 2009

Right after lunch today I had a host (3.5 U3) crach with a kernel panic. It shouldn’t be a problem for clusters running HA, but on this cluster I had disabled HA bacause of an error and hadn’t had the time to depug :-(. So my VM’s couldn’t be started on a new host and… Read More »

Windows Server 2008 and SYSPREP in a VMware enviroment

By | January 13, 2009

After we have allowed Windows 2008 Servers in our VMware VI enviroment, we been having problems sysprepping Windows 2008 Server. So here is a quick guide to sysprep a Windows 2008 server in a VMware VI enviroment. (Use this workaround until VMware VI allows you run sysprep against a WIN2008 Server) Change the source or… Read More »