Monday 31 July 2017

Virtual Machine - Edit Settings (CPU) Part 4(iv)

In my previous post, we have talked about Enable CPU Hot Add.
I am going to skip Reservations, Limit & Shares which will be covered along with calculations in a later post.



In this screenshot as you can see, I have used vSphere Web Client, Right Click on virtual machine & edit settings.


7.CPUID Mask: By default, VM is set to expose the NX/XD flag to guest.


This feature helps prevent execution of certain type of code.
Ex: Here, I have Windows 7 32-bit installed in which I have Enabled/Disabled this feature.

Default, Expose NX/XD flag to guest.

Later on, I Hide the NX/XD flag from guest (64-bit Windows Server 2012) I get this error.

I tried it on Windows7-32 bit, it has a feature DEP (Data Execution Prevention)






Sunday 30 July 2017

Virtual Machine - Edit Settings (CPU) Part 3 (iii)

In my previous post, I have talked about CORE.
Now in this Part 3, We are going to talk about ENABLE CPU Hot Add.



In this screenshot as you can see, I have used vSphere Web Client, Right Click on virtual machine & edit settings.


3.ENABLE CPU Hot Add: This feature lets you add or remove CPU resource to a powered ON virtual machine.
It should be supported by the operating system and should be turned on in advance i.e If VM is running then this option is grayed out. In order to turn it, VM should be in POWERED OFF state.


 

This information is from Windows Server 2012 R2 Standard Edition.


Once CPU Hot Add is enabled: 



This information is from Windows Server 2012 R2 Standard Edition.
Now if you want to decrease the number of CPU, that can only be done if VM is powered OFF.

We are able to edit get this CPU option, I have installed Windows Server 2012 R2 Standard Edition. VMware has published these KB articles related to CPU Hot Add Feature: KB2020993, KB2051989 which relates to this feature for various operating systems.









Saturday 29 July 2017

Virtual Machine - Edit Settings (CPU) Part 1 (ii)

In my previous post, I have talked about CPU.
Now in this Part 2, We are going to talk about CORE.



In this screenshot as you can see, I have used vSphere Web Client, Right Click on virtual machine & edit settings.

CPU Settings:-
2.CORE: Here I have shared an example of single socket , quad core processor.
Initially when VMware released CORES PER SOCKET, it was there to deal with software licensing issue. So as to reduce number of licenses , which were based on SOCKETS.  Further, for performance it is beyond the scope of this blog post which includes: NUMA, vNUMA CPU technologies.


An interesting example is given on this KB:2078069

Virtual Machine - Edit Settings (CPU) Part 1 (i)

In order to learn more, one has to explore more.
In this series of blog post, i"ll be talking about all the options one have for a virtual machine.

This is Part 1 of virtual machines & I"ll be explaining and giving real time examples for all these options which are available for a virtual machine. In the end, we want our virtual machines to be running healthy. Hell Yeah!!


In this screenshot as you can see, I have used vSphere Web Client, Right Click on virtual machine & edit settings.

CPU Settings:-
1.CPU: It depends on your physical processor(Socket & Cores Per Socket) that are present on your server.
As you can see in my case, what my host(ESXi) has, I can that as LCPU to my VM.
If there is no hyperthreading than the total number of LCPU =8 & if it is enabled then the total number of LCPU=16. VCPU(Virtual CPU for VM) is scheduled on LCPU(Logical CPU, part of core).

So, In my case, the maximum number of vCPU that can be assigned to the VM =16.