About the instanceUuid of vm

[watanabekazu]

According to vSphere API Reference,
"instanceUuid" is used by vCenter to uniquely identify
all vm instances.

Even if vm is deleted, its instansUuid is held uniquely in vCenter?
or Is its instansUuid assigned to other vm again?

Please tell me.

[William Lam]

That's correct, instanceUuid is unique per vCenter instance and it's guarantee to be unique. afaik, once an object has been deleted (e.g. VM), all it's information and identifiers are removed from the vCenter DB and it's instanceUuid can potentially be re-used. I would say this will probably be unlikely that you'll see the same instanceUuid again but it's definitely possible, so if you persist this in an internal DB, you may want to use another identifer as a key in case you find yourself in this corner case.

[Arun R]

When I create a replica of a VM, will the instanceUUID be the same or different?

[William Lam]

instanceUUID will ALWAYS be unique as that is managed exclusively by vCenter Server and it'll ensure they're always unique. For more details on instanceUUID, please see the various articles linked to https://williamlam.com/2014/07/what-happens-when-virtual-machines-have-duplicate-instanceuuids-on-esxi.html 

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William Lam
https://williamlam.com/
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