How many specific IDs each VM has??

[amircsco]

i'm really interested to know that how many IDs exists for a VM???

i did some search and i found that there are 15 unique and specific IDs associated to each VM, is it correct??

if yes, what make them unique and guarantee that two VM on to different ESXi Host  won't have the same IDs??

[vNEX]

Hi,
to identify objects/entities in vSphere environment there are two properties which ensures its uniqueness:
- instanceUUID (128-bit integer) [replacement for SMBIOS UUID]
- MoRef ID (vm-214; cluster-3 ...)

these are not only assigned to VMs but also to other VI "objects" like hosts, datacenters, clusters, datastores ...etc.
by combining instanceUUID with MoRef ID you can uniquely identify objects across multiple vCenter server instances.

For more detailed and precise info look at these great posts:
http://www.virtuallyghetto.com/2011/11/vsphere-moref-managed-object-reference.html
Uniquely Identifying Virtual Machines in vSphere and vCloud Part 1: Overview | VMware vSphere Blog -...
instanceUuid | VMware vSphere Blog - VMware Blogs
VMware KB: Looking up Managed Object Reference (MoRef) in vCenter Server
Design and Implementation Overview

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Regards,

P.

[amircsco]

Thank you vNex that was very helpful, i'm working with couple of ESXi single hosts in my Datacenter and for now i don't have any vCenter infrastructure.

so without considering datacenters, clusters, datastores i just need to find unique IDs assigned to a VM on a ESXi host. Also i would really appreciate if you can tell me that how many are they??

[vThinkBeyondVM]

If you do not have vCenter server.

One of the ways to know VM managed object reference (MO Ref)@VMs,datastores is to explore the managed object browser (mob) as follows:

Open browser >>open this URL>>"https://<Your ESXi host IP>/mob"  >>This will prompt you to enter ESXi credentials >>Then just explore.

[vNEX]

Hi,

in VM configuration file (.vmx) you will find the reference for UUID.BIOS (legacy UUID)

uuid.bios = "42 1f 87 31 af a3 7b c3-a1 ea c5 49 fe b3 e7 3e"

as I post it above you can also have a look at MOB for MoRef ID on the standalone host see KB1017126

instanceUUID if I understand it correctly is vCenter server specific identifier.

Thanks

Regards,

P.

[amircsco]

i appreciate for your responses guys  but unfortunately still i don't have efficient answer to my issue.

[vNEX]

Whats the issue?

On standalone host they are two for the VM object:

-BIOS.UUID

-MoReF

Regards

P.

[vNEX · Accepted solution]

MoRef ID on ESXi host can change in situations like vMotion, Storage vMotion, DR restore, Full restore from backup etc.

Bios.UUID is static unique identifier...

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EDITED to correct information