arduinoAndMore
Contributor
Contributor

Duplicate UUID's for VM's

Background

About 2 months ago I built a new ESXi server (v. 6.0.0) to run a new DC and file server.  I built the DC up to a point and then tried to make a template/clone it so I could more quickly build the file server.  It seems that plain ESXi (no vSphere) doesn't do that, so I wound up trying to just copy the files to make a clone.  That worked just fine as far as I can tell, and the servers have been in production for a little over a month. 

My drives for the backup server have arrived, so now I'm trying to build my Unitrends box and get backups going.

Question

When I try to add this ESXi host to the Unitrends backups, Unitrends complains about my DC and file server having the same instance UUID.  I found another community thread that said to power off the machine and edit the uuid.bios line in the vmx file.  I tried that, but it seems to give the same error.  Does anyone have a suggestion?

Tags (2)
0 Kudos
11 Replies
vXav
Expert
Expert

0 Kudos
arduinoAndMore
Contributor
Contributor

@vXav It sounds similar, but when I run the command


vmkfstools -J getuuid <vmname>.vmdk


I get different UUID values for the two machines in question.  I tried to check the others, but most of them (which are powered off...probably permanently) just say


The virtual disk does not contain a UUID


The two machines in question return the following:


UUID is 60 00 C2 9d e0 a6 61 dd-58 2d 93 18 e9 dc bb e5

UUID is 60 00 C2 93 08 29 8d 86-42 41 35 c4 a6 d6 66 e8


Obviously those are different, so I don't see how Unitrends is finding duplicate anything.

0 Kudos
arduinoAndMore
Contributor
Contributor

Addidional Info:

Here is the error from Unitrends.  I hope this will help to clarify the issue.  I'm not sure what exactly an Instance UUID is, so maybe the extra specificity will help someone figure it out.

001321.jpg

Thanks!

0 Kudos
vXav
Expert
Expert

Ok, run that in powershell/powercli.

get-vm | get-view | select name,@{l="uuid";e={$_.config.instanceuuid}} | export-csv ~\desktop\VmInstanceUUID.csv

Then open the CSV and ctrl-f or sort by UUID.

You'll see if there is a duplicate.

0 Kudos
arduinoAndMore
Contributor
Contributor

@vXav The output of that command does indeed show a duplicate value on the two machines that unitrends is complaining about.  I wonder why this command shows different UUID's than the one I documented above.  Maybe it's a different type of UUID.  I believe it has more dashes as well.  Anyway, now I know there IS indeed a duplicate.  What now?

Thanks for your help!

0 Kudos
virtualg_uk
Leadership
Leadership

If you need to change the UUID, then you need to change this in the VMX file and in the VMDK descriptor files.

There is more information about this here: http://www.derekseaman.com/2010/10/making-your-vmware-vm-uuids-unique.html

and https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1541

You could also try powering off the VM and cloning it to generate new UUIDs for the disks?

I hope this helps


Graham | User Moderator | https://virtualg.uk
0 Kudos
vXav
Expert
Expert

Or unregister it, and register it on another host. Then ith should display the message "Have you moved or copied this VM" and click copied.

0 Kudos
arduinoAndMore
Contributor
Contributor

@grba

I ran the script, but it didn't take effect on the machines that are still powered on.  I went and checked the UUID's it did change (those that were powered off) and they seem to have set the uuid.bios value in the corresponding vmx file.  I set a new value in one of my vmx files manually yesterday, and it still gives this error.  I first powered off the file server, then downloaded, edited, and then replaced the vmx file after changing the uuid.bios line.  I powered up the machine again and I get the same error.

You mentioned a vmdk descriptor file which needs to be modified, but I'm not aware of that file.  What is it called and what needs to be changed?

@vXav

What do you mean register it on another host?  I've only got one ESXi host at that site.

Thanks for the replies

0 Kudos
arduinoAndMore
Contributor
Contributor

Nothing thus far has worked.  I've tried everything suggested so far.  Please help!

0 Kudos
vXav
Expert
Expert

If you have one host then, try to unregister the VM then re-register it and see if vCenter changed the uuid.

If it doesn't work can you try to clone the VM and see if it duplicates again? If not you can then use the clone. Not ideal but ...

0 Kudos
virtualg_uk
Leadership
Leadership

vmdk descriptor file which needs to be modified, but I'm not aware of that file.  What is it called and what needs to be changed?

The descriptor file is meta-data for the VMDK disk. It's name is usually VM-Name.vmdk it is human readable and contains a line for the UUID as does the VMX file. The data for a VMDK is called VM-Name-flat.vmdk this is not human readable.

Once you change a UUID, you can verify that it has been completed correctly by running:

# vmkfstools -e filename.vmdk

For a complete chain, you see output similar to:

Disk chain is consistent

For a broken chain, you see a summary of the snapshot chain and then an output similar to:

Disk chain is not consistent : The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child (18)

Recreating a missing virtual machine disk descriptor file (1002511) | VMware KB


Graham | User Moderator | https://virtualg.uk
0 Kudos