VM with more than 128 vCPUs

[EBoucq]

Hi,

I need to add vCPUs to a VM. This will exceed 128 so I'm getting this message "The firmware boot option setting has been automatically changed from BIOS  to EFI as well as I/O MMU has been enabled to allow for the specified CPU".

I can't find any information about this message on the net so I'm wondering what the consequences are for my VM / OS. Do I have to change anything on the OS level ? What are the risks for my machine ?

(FYI: ESXi 6.7 U2 / VM SLES 12)

Thanks a lot for your future replies.

Eric.

[continuum]

In simply terms this means that
- a VM with BIOS firmware can not have more than 128 vCPUs.
- a VM with more than 128 vCPUs needs EFI
- changing the number of vCPUs above 128 will render a VM with BIOS unbootable.
======================================

You must create a new VM with EFI to get more than 128 vCPUs.
Ask in the SLES forums if there is a way to switch from BIOS to EFI.
If there is a way to do that it will not be trivial : you need a special additional partition and different bootloaders ...

Ulli

[EBoucq]

Thanks Ulli !