how can i easily tell if i have too many cpus and memory in my virtual server

If the server was physical, would they need 6 CPU or 12 CPU machines?

because I've not seen 6 or 12 physical CPU machines.

It's a well known fact in "hypervisor circles!"

print this out.....

vSMP (virtual SMP) can affect virtual machine performance, when adding too many vCPUs to virtual machines that cannot use the vCPUs effectly, e.g. Servers than can use vSMP correctly :- SQL Server, Exchange Server.

This is true, many VMware Administrators, think adding lots of processors, will increase performance - wrong! (and because they can, they just go silly!). Sometimes there is confusion between cores and processors. But what we are adding is additional processors in the virtual machine.

So 4 vCPU, to the VM is a 4 Way SMP (Quad Processor Server), if you have Enterprise Plus license you can add 8, (and only if you have the correct OS License will the OS recognise them all).

If applications, can take advantage e.g. Exchange, SQL, adding additional processors, can/may increase performance.

So usual rule of thumb is try 1 vCPU, then try 2 vCPU, knock back to 1 vCPU if performance is affected. and only use vSMP if the VM can take advantage.

Example, VM with 4 vCPUs allocated!

My simple laymans explaination of the "scheduler!"

As you have assigned 4 vCPUs, to this VM, the VMware scheulder, has to wait until 4 cores are free and available, to do this, it has to pause the first cores, until the 4th is available, during this timeframe, the paused cores are not available for processes, this is my simplistic view, but bottom line is adding more vCPUs to a VM, may not give you the performance benefits you think, unless the VM, it's applications are optimised for additional vCPUs.

See here
http://www.vmware.com/resources/techresources/10131

see here
http://www.gabesvirtualworld.com/how-too-many-vcpus-can-negatively-affect-your-performance/

http://www.zdnet.com/virtual-cpus-the-overprovisioning-penalty-of-vcpu-to-pcpu-ratios-4010025185/

also there is a document here about the CPU scheduler

www.vmware.com/files/pdf/perf-vsphere-cpu_scheduler.pdf

https://blogs.vmware.com/vsphere/2013/10/does-corespersocket-affect-performance.html

we have a oracle server that has 24 cores
when configuring is there any majot difference between
adding them as 1 virtual socket with 6 cores or 6 virtual sockets with 1 core

No difference....

Cores is useful if you have license restrictions....

otherwise I would stick to using sockets....

last link of my first post...

https://blogs.vmware.com/vsphere/2013/10/does-corespersocket-affect-performance.html

what is classed as high cpu ready and co-stop for a vm
does this still apply as much to 5.5

Applies to all Hypervisors.

from the article:-

READY: The time a virtual machine must wait in a ready-to-run state before it can be scheduled on a CPU
CO-STOP: Amount of time a SMP virtual machine was ready to run, but incurred delay due to co-vCPU scheduling contention.

http://www.gabesvirtualworld.com/how-too-many-vcpus-can-negatively-affect-your-performance/

yes but i mean what would be classed as a high cpu ready and co stop time in ms