Virtualization, Cloud, Infrastructure and all that stuff in-between

My ramblings on the stuff that holds it all together

vSphere RC RAM Under VMware Workstation: How Low Can You Go?


Getting ESX (in it’s various versions) to run under VMware Workstation has proven to be a very popular article on this blog, if you are a consultant who has to do product demos of VI3/vSphere or are studying for your VCP it’s a very useful thing to be able to do on your own laptop rather than rely on remote connections or lugging around demo kit.

Good news; the RC build of vSphere will boot under the latest VMware Workstation build (6.5.2) without any of the .vmx hackery you had to do in previous versions and it seems quite fast to boot.

Bad news: the RC build of vSphere needs at least 2GB of RAM to boot, this is a problem for a laptop with 4GB of RAM as it means you can only really run one at a time.

Luckily: Duncan Epping (or VCDX 007; licenced to design :)) has discovered how you can hack the startup script to allow it to run in less than 2GB of RAM – details here, this isn’t officially supported – but it does work.

In the interests of science I did some experimentation with VM’s with various amounts of decreasing RAM to see what the bare minimum RAM you can get away with for a VM’d version of vSphere RC.

The magic number seems to be 768Mb of RAM, if you allocate less than this to the VM then it results in a Purple Screen of Death (PSOD) at boot time.


Note – this may change for the GA/RTM final version – but these are my findings for RC

The relevant section of my /etc/vmware/init/init.d/00.vmnix file looks like the following (note it won’t actually boot with 512mb assigned to the VM)


Some screen captures of the vSphere RC boot process below

image image

And finally the boot screen once it’s finished – it takes 2-3 mins with 768Mb of RAM on my laptop to get to this boot screen.


I am doing this on a Dell D620 with 4Gb RAM and Intel VT enabled in the BIOS, running Vista x86 and VMware Workstation v6.5.2 build 156735



I haven’t tried, but I assume I can’t power on VM’s under this instance of vSphere but I can connect them to a vCenter 4 machine and practice with all the management and configuration tools.

Happy tweaking…

12 responses to “vSphere RC RAM Under VMware Workstation: How Low Can You Go?

  1. Vladan May 8, 2009 at 1:50 pm

    I wonder where to get the vSphere 4. It’s still in BETA right? But not public…

    • vinf May 8, 2009 at 6:53 pm

      Yes, still in beta – but the final version is available from 21st May I believe the beta was private, accessible via application through your VMware account manager

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  3. adri May 17, 2009 at 5:50 pm

    can I run that lab on a PC, what minimum PC hardware requirement that I can test with smoothly.

    • vinf May 18, 2009 at 8:02 am

      I’m using it on a Dell D620, 7200RPM HDD, 4GB ram and an intel core 2 CPU @2GHz and it works ok for me – just make sure you use something that has (or can support) Intel VT or the AMD equivalent.

      Works ok for me.

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  5. ali May 24, 2009 at 6:59 am

    Hi All, your solution does not work for the GA Release ;-(
    Is there already a workaround for the GA version available ?

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  7. kevin February 3, 2010 at 1:12 pm

    I am unable to get this to work using Windows 7 X64 and vmware workstation 7. I can edit the 00.vmnix file to a lower memory amount but I continue to get the memory error. It will only boot if I assign the ESX VM 2 GB and nothing less.

    After it boots I go back to check the 00.vmnix file and it is what I set it to previously so that setting is working but in vmware workstation 7 my ESX VM must have 2 GB or the memory message appears.


  8. Sanjay Joshi January 1, 2011 at 3:25 pm

    your solution does not work

    • January 12, 2011 at 9:57 am

      Thanks for your comment and apologies for the delay in replying; I believe this “hack” only worked for the RC build (as noted in the title) rather than the final version

  9. Pingback: No title » Blog Archive » Running ESX(i) 4.1 with less than 2GB RAM

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