Vcpu tweaking...

[Davek0974]

Hi all,

On the vcpu tab in esxi5 , it states that adjusting the CPU or core values may render the vm inoperable, is this going to be permanent I.e if I reset them values back to how they were it will work ok again or is it likely to be fatal??

I have a vm that I think needs more but don't want to risk corruption.

Thanks

Dave

[weinstein5]

If you revert back tp the original setting the shoud work if you run into issues - for most operating system there should be no problems adding vcpus but their are some instances where you can run into issues - like earlier versions of Windows require HALs that were specific to SMP or non-SMP machines -

[eeg3]

I have only seen this on very old versions of Windows, as weinstein5 said. I've never seen it occur on up to date 2k3 or 2k8. Ultimately, you should be able to revert back to the current number of vCPUs so it isn't a permanent-breaking issue.

[MagnetBoy]

Hello,

I have done this a lot of times with no issues.  Windows 2003 32bit, Win2003 64bit, Windows 2008, Windows 2008 R2, etc.

Now, if you do not want to take the risk then try this:

1. Clone VM1 (VM1-clone)
   
2. Add vCPU's to the clone and check it.  If there is 0 issues, then
   
3. add any # of vCPU's to the original VM1
   
4. done!
   

[Davek0974]

Great stuff, thanks.

I'll have a play then

Btw the oldest OS is xp sp3.

Dave