In Vsphere 6.7 where on earth are the Advanced CPU HT Sharing:  Options!!!!

JB Blanco
JB Blanco used Ask the Experts™
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In Vsphere 6.7 where on earth are the Advanced CPU HT Sharing:  Options!!!!  I have looked in both the HTML and Web client and cant find these options!

Here is a screenshot from Vsphere 5.0 console showing clearly where these options are located:
Edit VM
Can anyone help point me in the right direction?

I need these same options because I do not want to share any CPU with any other vm so I need to find this same option in Vsphere 6.7 and choose "None"

Thanks
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Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
It has not been a feature since 5.0.

Gone ski.

see here

Hyperthreaded core sharing is only supported for ESXi hosts version 5.0 and earlier.

Source
https://docs.vmware.com/en/VMware-vSphere/5.5/com.vmware.vsphere.vm_admin.doc/GUID-101176D4-9866-420D-AB4F-6374025CABDA.html

Community reference as well...

https://communities.vmware.com/thread/576045
Top Expert 2014

Commented:
>"I do not want to share any CPU with any other vm"

Maybe you mis-worded that? Cores are always shared in time slices.
JB BlancoSr Systems Engineer

Author

Commented:
>"I do not want to share any CPU with any other vm"

Maybe you mis-worded that? Cores are always shared in time slices


Well I want the same effect that I would get in Vsphere 5.0 if I set HT Sharing to None basically

Can you point me in the right direction?
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Top Expert 2014

Commented:
I think you would have to turn HT off in BIOS on all the hosts.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
This may come as a surprise to learn that the function "HT Sharing" did not work, after 5.0.

in vSphere 5.1 it stopped working, but VMware (never fixed) never removed it from the GUI, so VMware Administrators selected it in 5.1 and 5.5 believing it was doing HT Sharing but it never really did!
(a great placebo!!!). Many still believe it did work and help them, but there is clear evidence it broke in 5.0, and never worked again.

if you have patched correctly you will find, that you  no longer have double the cores (e.g. effectively hyper threading has been turned off!).

If you have a VM that only wants the best and nothing but the best performance...

You should

1. Enable Full Cores Reservations.
2. Enable Latency Sensitivity.

The CPU scheduler will then ensure no other world is scheduled on the logical processor, when a vCPU is with exclusive reservations scheduled on the cpu core.
JB BlancoSr Systems Engineer

Author

Commented:
If you have a VM that only wants the best and nothing but the best performance...

You should

1. Enable Full Cores Reservations.
2. Enable Latency Sensitivity.

The CPU scheduler will then ensure no other world is scheduled on the logical processor, when a vCPU is with exclusive reservations scheduled on the cpu core.

Thanks for your help!,  So here is what the server request form is asking for:  "CPUs: 4 (RESERVED), RAM: (GB) 16 (RESERVED)" When I see (RESERVED) for CPU,  I assumed HT Sharing = none.    So now on 6.7, how should I configure the VM in "Edit Settings" To get the same effect?  This VM will be on ESXi hosts in a cluster where a lot of other VM's reside.   So Obviously I don't want to mess up anything for the current residing VM's already in that cluster.  They are production VM's.  So I do see the following options:
cpu I was gonna mess with Reservation and set a certain speed, but will that have the same affect?  This Particular VM will be a sql server.
VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017
Commented:
You CANNOT get the same effect, the function does not exist, it never worked. (after 5.1).

But you can enable Latency Sensitivity, and reserve ALL the CPU , which will ring fence, and stop any other VM stealing it's CPU resources.

Select VM > Edit Settings > VM Option > Advanced > Latency Sensitivity > HIGH.

this will then suggest to edit the CPU Reservations and set to 100%. So specify the MHz or GHz you require for this VM.

(as for your form, I'm not sure if they know what they are asking).

As for messing up other VMs on the Production Cluster, if you start RESERVING CPU and Memory, you do not make it available for other VMs, and you are effectively working against the hypervisor scheduler, which could have a detrimental effect depending upon the current load on the host. (depends on current usage, and if oversubscribed).

e.g. your new SQL server may not be doing anything, but the host can no longer borrow resources CPU and MEMORY for other Guest VMs.

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