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vSohill
Expert
Expert

vmware 1:1 processor mapping virtual to physical cores

Hi ,

I need your help to set ratio for 1:1 processor mapping virtual to physical cores, this ratio will not be vaiolated  by deploying any new VM or migrating VMs too.How can I set this limit?

Thank you

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Techie01
Hot Shot
Hot Shot

If I understand the requirement correctly, you are looking for cpu affinity. Refer https://pubs.vmware.com/vsphere-55/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-55-resour... ( page 25)

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hussainbte
Expert
Expert

I don't think there is any alarm or advanced configuration parameter that will monitor the overall number of virtual core to physical cores on the esx host and will prevent further deployment.

also, unless are deploying all Microsoft Exchange, or SQL server or other CPU intensive machine there is no point keeping such a ratio. you will miss on some basic benefit of virtualization, over subscription

If you found my answers useful please consider marking them as Correct OR Helpful Regards, Hussain https://virtualcubes.wordpress.com/
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vSohill
Expert
Expert

Hi Teche01,

Thank you for your help, What I am looking for is to garante a ration between vCPU: pCPU for example 4 vCPU to 1 pCPU and the host or addmission control will not allow over than an dedicated ration

thank you

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hussainbte
Expert
Expert

That is not possible

If you found my answers useful please consider marking them as Correct OR Helpful Regards, Hussain https://virtualcubes.wordpress.com/
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vSohill
Expert
Expert

Why is not possible ?

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TXMatt
Contributor
Contributor

They are correct in stating that a 1:1  V to P reservation is not possible, simply put - the options are not there (that I have seen).

But as a potential solution you can manipulate CPU speed reservations to achieve the same concept.

Using the speed equivalent of a single CPU, you reserve that amount to the VM with 1 vCPU(core), creating a 1:1 relationship.

If you follow this for all VMs under a single host, eventually the processing power of the host will be divided out and prevent other VMs from powering on.

Concept Example:

HostA - 2 x CPU @ 4ghz each for a total of 8ghz processing power

VM01 and VM02 would reserve 4ghz each of processing speed for each single core they are configured with.

With those two powered on,

VM03 regardless of reservation would not be able to power on.

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