Node1
Summary View
Physical
sockets=2 , Physical CPU per socket= 1,
Core Per CPU=4
Total
Computing power is :- 8x2.294 GHz=18.352
GHz
Here
we have not enable HyperThreding so total logical Processors its showing is = 8
Logical processor
If
we enable hyperthreding then we should get double of it i. e 8x2=16 Logical processors
but this will not increase total computing
power because it is depend on your total core and not logical processors……….:)
Below figure shows that after enabling Hyperthreding in 2
sockets Node with 4 cores per sockets.
It showing 16 logical processors……………Grt
2 (sockets) x 4 (Cores per sockets) x 2 (Hyperthreding) = 16
logical Processors
But total compute capacity i.e. CPU Capacity is= 8 (total
cores) X 2.393 GHz
Below is the Virtual machine running on 3 node cluster
Now here we have given 1 vCPU and 2 GB RAM to this Virtual
machine and install Windows 2008 R2 Enterprise Edition 64 Bit OS
In windows its showing Quad-Core AMD processor with 2.29 GHz
and in task manager its showing 1 core of processor.
And my node is licenced with Enterprise licensed type its
showing 6 cores per CPU
And with enterprise plus licensed type its gives 12 core per
CPU and 8 way virtual SMP
Now when I tried to edit the Virtual processors and change
it to MAX available value i.e. 8
Ok now I change the vCPU from 1 to MAX 8 and try to boot the
Virtual machine………
Ohh no there is an error …….
It says that virtual machine has 8 virtual CPUs but host
support only 4. Oh no, then I am not
able to use 8 vCPU.
I went to check where the exact problem is? Is this the
guest OS limitation or my host licence?
My guest OS is Windows 2008 R2 Enterprise Edition which
Supports Upto 8 CPU then it must be a problem with Host License ok let me check
that as well.
Ok here is my license type Enterprise License with 2
physical CPUs and 1-6 Core per CPU
It looks good then what is the 4-Way virtual SMP ………
Here is the definition of SMP from VMware
“4-Way VMware
Virtual SMP (symmetric multiprocessing). With the power of up to four physical
processors available to each virtual machine”
Now we can conclude that 4-way SMP it the blocking point for
us, so we can’t use more than 4 vCPU to any guest regardless of Guest OS type.
Let’s check by giving 5 vCPU to same guest………….
Yah same error
So I give 4 vCPU and started Virtual machine.
Ok I have one more server node of ESX having different
license file.
Here its enterprise plus and 8 way SMP
And I checked here Virtual machine with windows 2008 R2 Ent.
Edition having 8 vCPU
And in windows its
showing 8 processors wow gr8.
From above figure we can see how memory has been allocated
to Virtual machine
Starting from bottom 512 MB and 4 GB are the default memory
Tab from Operating system, as guest os is windows 2008 so recommended is 4 GB.
Now third tab is “Maximum recommended for best performance”
and it’s 32GB Ohh what is that?
Its MAX memory installed on Node... Remember we have 32GB
physical memory installed on Node1.
Ok then what is the fourth Tab about 255 GB RAM…ok now we
can get that this is the max memory supported by that Node as per our ESX
license file ……256 GB max supported in Enterprise license
And for enterprise plus there is no RAM limitation.
2.294 GHz X 4 vCPU = 9.176 GHz total computing power
allocated to Virtual Machine
CPU resource allocation
Share: - Low=1, Normal=2, High=4
So in above condition when Low share selected it allocating
Share Values
|
||
For example, an SMP
virtual machine with two virtual CPUs and 1GB RAM with CPU and memory shares
set to Normal has 2x1000=2000 shares of CPU and 10x1024=10240
shares of memory.
Virtual machines
with more than one virtual CPU are called SMP (symmetric multiprocessing)
virtual machines. ESX/ESXi supports up to eight virtual CPUs per virtual
machine. This is also called eight-way SMP support.
The relative priority
represented by each share changes when a new virtual machine is powered on.
This affects all virtual machines in the same resource pool. All of the virtual
machines have the same number of VCPUs. Consider the following examples.