seangarland
Contributor
Contributor

Rebuild pool from cloned desktop

Hello all!

A while back I did some Windows updates to "main" desktop for a cloned desktop pool.  I then did a recompose to push out the updates.  After some time, it was discovered that one of the many manufacturing apps that they use in the VDI wasn't working.  Only one stations, one of the cloned desktop pool computers that hadn't recomposed, was working correctly. 

Here is where I screwed up:  In an attempt to fix the issue, we discovered that the image was out of hard drive space.  The software vendor and I figured this was the reason (Windows updates taking up more room) why the software was failing.  I removed snapshots (yeah I know), but this did not fix the glitch.  At this point I had the 00 computer not working, as well as 5 of the 6 pooled desktops.  Only the 6th was working flawlessly.

At this point, I tucked the original 00 away, and made the 06 one the 00 one.  I did a snapshot, and performed a recompose from the new snapshot (being a snapshot of a cloned desktop).  NOW all of my pool computers have the same name (00), and after 30 days or so, they all lose their connection to the domain (trust relationship). 

Is there any way to make the (now) 00 desktop appear to the system as if it really is the original desktop, with swap files and everything working right?  It's all messed up right now, and the swap file, scratch ram, machine name, and now the trust all seemed to be messed up.  The manufacturing software takes HOURS to install, or I'd just start over (which I may end up doing), but maybe someone has a "oh man, just edit this registry key, and BAM" type revelation....

Thank you all in advance!!!

Sean Garland

Garland Tech

5 Replies
sjesse
Leadership
Leadership

Might want to check with a microsoft expert, but I think if you clone a vm thats joined to the domain, all vms will connect to the same object. I think what you need to do is clone that vm, remove it from the domain, run sysprep on it, and then recompose your pool. As long as your not using appvolumes or something based on the SID, you should be fine.

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BenFB
Commander
Commander

During a recompose by default quickprep (or if selected sysprep) will run and rename the linked clone from the original parent name to the new name specified by the naming scheme. Are these linked clones that you are manually renaming?

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sjesse
Leadership
Leadership

I think the key if a linked clone is being cloned to a full clone, and repurposed for a parent image, you have to remove it from the domain and readd it before you recompose. If I remember right there is the local SID and a domain SID. The domain sid is recreated when you connect to a computer object, and thats stored on the desktop. When you clone it that desktop, it will connect to the domain using the same object

https://blogs.msdn.microsoft.com/aaron_margosis/2009/11/05/machine-sids-and-domain-sids/

I think quickprep does leave the domain and does the rejoin, but I would manually do it to make sure.

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BenFB
Commander
Commander

I was looking for something unrelated in the documentation and stumbled across this recently. It's not supported to use a converted linked clone as a parent virtual machine.

Configure a Parent Virtual Machine

Verify that the virtual machine was not converted from an instant clone or a View Composer linked clone.

Important:

You also cannot use an instant clone or a View Composer linked clones as a parent virtual machine.

sjesse
Leadership
Leadership

good catch I remember reading about that now. Maybe if you uninstall vmware tools and horizon agent it might work, but if they out right say it, there is probably some junk that gets left behind that causes problems.

Sean you might be better off rebuilding the parent, but what I would do is keep that seperate then parent images you use, and take snapshots after each update. Then clone the snapshot to your parent, take a snapshot for the cloning process, and then push it out.

Thats the process I've been following for our instant clones, we don't have applications on them. but it helps with falling back if we need. I think the term is golden image and parent image. They suggest that in this guide as well

Creating an Optimized Windows Image for a VMware Horizon Virtual Desktop | VMware

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