Lately, it has become a portal for me to blow off steam and rant about various technical woes I have. You see, even a vExpert and certified Guru has their challenges.
Anyway, recently I had a “challenge” (such is the vague euphemism that annoying problems go by these days!). It concerned cloning Windows 7 (and occasionally Windows 2008) machines. The blogpost about that problem is here, and the error I was getting was this one:
I kind of walked away from this problem in disgust. I decided to use Windows XP for my virtual desktop pools to avoid this kind of issue. Then I had problems with Windows XP! So I turned back to Windows 7 and this problem.
Anyway, I think I found the cause. I did another googlewack. Using the search string of sysprep and the entire string from the offending dialog box, I found this in the release notes for Vi3. Incidentally, this should also apply to vSphere4 as, strictly speaking, it's not a VMware issue.
Customization Specification of Windows Server 2008 or Windows Vista Guest Operating System Can Only Be Changed Thrice Successively
Consider a virtual machine running Windows Server 2008 or Windows Vista. You can clone this virtual machine with customization, and edit the customization specification of the clone to create another virtual machine. However, only three such successive cloning operations can be performed. ?For example, if virtual machine A is cloned to virtual machine B, virtual machine B is cloned to virtual machine C, virtual machine C is cloned to virtual machine D, and the customization specification of the guest operating system is edited for every clone operation, then an operation to clone virtual machine D with customization might fail.
This might be the cause. Here's how. Let's say I have a Windows 7 template. I then decide I want a clone of this so I can install the Beta/RC View 4.5 Agent to the VM. Next, I clone this VM to make another copy to install VMware Tools. I’m worried that the pesky SVGA 3D Driver might cause problems with PCoIP and decide that having a clone is better than working from endless nested snapshots. Next, I clone this VM to make a Parent-VM, and so on. The cloning of a clone of a clone can result in this limit being reached very quickly.