Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have several ESX 3/3.5 servers (a few standalone 3.01 and the cluster is all 3.5) and every now and then I get an MKS error when accessing a VM console (10% of VM's).

Looking on the VMWare forums no one seems to have a definitive answer. From what I can gather the usual suggestions are

  1. Make sure your VI Management Console is up to date (or at least appropriate for the ESX version you're controlling).
  2. Make sure the Service Console gateway address is working as expected because the VM sends the console output back through the Service Console.
  3. On a related note a few people have mentioned that the VM itself needs to know how to get back to the Virtual Center or VI Management Console - I can understand this for RDP or explicitly network related stuff but I thought the ESX server essentially 'screen scraped' the VM console and sent it back via the Service Console.

Now the strangeness is that these responses don't operate with any particular consistency (ie some VM's display the console fine and some don't with exactly the same settings). For our internal LAN a lack of console isn't such a big deal - the template has RDP and DHCP enabled by default but in the DMZ a lack of console is a little more problematic.

Does anyone have any good advice on troubleshooting MKS faults ?

Thanks in advance, Raj.

share|improve this question

What might help is making sure you have the following setting on all the affected ESX servers:

/etc/vmware/config file needs the line

vmauthd.server.alwaysProxy = "TRUE"

Here's more info on this issue, it appears to be a bug which should be fixed in later releases:

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.