Before I start with the article, I have to point out this is not a VMware bug. Its the VMware admins doing what they are not suppose to do. VMware ESX 3 & VMware ESX 4 Administration Guides mention clearly that you should not VMotion or Storage vMotion a Virtual machine before disconnecting it from CD Media & ISO images that is only available to the first host or Datastore. Actually it will even warn you when you trying to do that.
That has been said, I still have a good number of customers who call me about their Virtual Machine summary still showing that it has a disk on the old datastore after Storage VMotion it to a new datastore. In most cases, it end up that the customer has carried out a Storage VMotion on a virtual machine that is connected to an ISO Image on the old datastore (probably where they have installed the VM from) see the image below.
Luckily the solution is quite easy, all you have to do is just change the Virtual Machine CDRom setting to Client Device & Hit OK as per the image below:
Now you should only see the new Datastore in your Virtual Machine. Although this is an easy solution, many people will miss it. I mean specially when you you are under pressure or have not faced it before.
I hope this tip help someone, & sorry if this tip is too easy for you :). Please leave a comment if it helped.