Virtual Wood Blog

VMware, vSphere, ESX, ESXi, PowerCLi and everything else

Virtual Wood Blog - VMware, vSphere, ESX, ESXi, PowerCLi and everything else

Monthly Archives: April 2011

Running nested virtual machines

In this blog I will explain what changes are need to allow a nested virtual machine to be powered on inside a virtual ESX host. This is something that I have been using to allow for study of the VCAP in a limited LAB situation.

The setup I have is physical ESXi 4.1 hosts on which I made a datacenter and cluster for LAB use. Inside this cluster I built 3 ESXi 4.1 hosts which have to be configured with the following disk configuration and OS selection:

  • LSI Logic SAS
  • Red Hat Enterprise Linux 6 (64bit)

Once the ESXi 4.1 hosts are built and everything else is configured the vmx file of each host needs to be edited. This will enable the virtual hosts to run virtual machines in the future. The lines that need to be added are as follows (I just added these lines to the end of the vmx file):

  • monitor_control.restrict_backdoor = "true"
  • monitor_control.vt32 = "true"

To add the above lines to the vmx file will require the file to be downloaded from the datastore and edited (for this I use Notepad++). The edited files are then uploaded back to the datastore (for good measure I remove the virtual machine and add it again to the inventory).

These additions will mean that nested virtual machines are now able to power on and the environment function like a physical one.

By Paul Wood

Changing the ip address of the vMA

During the initial setup on first boot of the vMA the configuration screen will ask questions regarding to ip address and hostname. If during this process an error has been made it is possible run the initial setup again.

I had this very issue as by mistake I selected "yes" to using DHCP. I spent some time looking at conf files but then found a reply on the VMWare forums that had the answer.

Go to the console screen of the vMA which will if it has just restarted prompting for a password to be set. Once this is complete follow the steps listed below:

  1. Press Alt F2 to get to the login screen
  2. Login using vi-admin
  3. Type cd /opt/vmware/vma/bin
  4. Type sudo ./vmware-vma-netconf.pl

This will come up with some rather comical text and the vi-admin password will need to be entered again. Once this has been entered the initial setup will run again allowing for any errors to be corrected.

By Paul Wood

Running vMA 4.1 on VMware Workstation

I came across this issue as I run my LAB as stated before on a laptop which means I cannot run x64 virtual machines on my ESX installations. After a quick search I came across a post by Kenneth van Ditmarsch which took me through the exact problem and below is the fix that I have tried and tested.

I have edited the two lines that need to be changed due to the "" that had been used. If the original version had been copied and pasted then the file would not work and the virtual machine fail.

After importing the new vSphere Management Assistant (vMA) 4.1 on my VMware Workstation 7 environment I noticed that it the virtual machine boots with a memory crash error. The error is “unable to access resume device” message and eventually ends with a kernel panic screen shown below.

The memory crash error can be ignored after checking CentOS blogs. The reason why the vMA virtual machine is hanging is due to the fact that its SCSI card and OS type needs to be changed in the .vmx file

Follow the steps below (credits to Justin for pointing this out to me!)

  • Remove the vMA from the VMware Workstation Inventory
  • Open the .vmx file and change the following to lines to be:

    scsi0.virtualDev = "lsilogic"
    guestOS = "rhel5-64"

  • Add the vMA back to VMware Workstation and boot it up.

Once the vMA has booted succesfully the configuration screen will be see. At this point follow vSphere Management Assistant Guide which will advise on how the vMA should be setup.

By Paul Wood