vmware cpu vs core - understanding the licensing

Question

vmware cpu vs core - understanding the licensing

david.robertson

SSC Veteran

Points: 269
More actions
November 18, 2008 at 10:11 am

#196373

Hi,
We are planning to deploy sql2005 on an ESX host.
The host is a 4 cpu machine with 16 cores on each to give a total of 8 cores.
If this was a physical machine, I would purchase 4 sql server processor licences.
In the VM world, we create a guest, and assign a number of virtual cpus to this. In reality, these are only cores.
If I assign 4 cores to this does a single cpu license cover this or due to the underlying mechanisms that vmware uses, does I need to take into account the other cpus?
If the above is true, is there anything I can do with processor affinity etc.. to get round this issue.
Many thanks

Viewing 6 posts - 1 through 5 (of 5 total)

You must be logged in to reply to this topic. Login to reply

Perry Whittle SSC Guru Points: 234013 More actions · Answer 1

SQL2005 must be licenced per virtual processor. However if you licence the physical sockets on the host box you are covered for unlimited virtual cpus\VM's on that host

check for more info here

http://www.microsoft.com/Sqlserver/2005/en/us/pricing-licensing-faq.aspx

-----------------------------------------------------------------------------------------------------------

"Ya can't make an omelette without breaking just a few eggs" 😉

david.robertson SSC Veteran Points: 269 More actions · Answer 2

Thanks for the reply.

I have read something similar to that. The issue is with the wording. Is a virtual processor a core?

Take for example the simplest setup.

SQL Server on a 1 cpu machine with 4 cores running sql server standard.

If this was on physical tin, we would need 1 sql license.

If this was on VMWare, we would present out 4 cores. Do we need 4 licenses as there are 4 virtual cpus represented.

Some background on this if it helps. We are planning on putting one vm sql server into an esx cluster. In my mind, we should be able to present out 8 cores representing 2 real cpu. If this isn't the case, I'm as well putting it on physical tin.

Perry Whittle SSC Guru Points: 234013 More actions · Answer 3

that's not how it works, a virtual CPU has no knowledge of cpu cores. The physical host is licenced per physical socket. You need to weigh up your licensing requirements. If you plan to have multiple SQL vm's then licence the physical host, if only one then licence the virtual CPU in the VM. Note that if licensing the host and using Vmotion any host the vm moves to will require licensing too.

-----------------------------------------------------------------------------------------------------------

"Ya can't make an omelette without breaking just a few eggs" 😉

david.robertson SSC Veteran Points: 269 More actions · Answer 4

Thanks again for the reply.

I have found an excellent resource from microsoft explaining how it works.

http://download.microsoft.com/download/3/d/4/3d42bdc2-6725-4b29-b75a-a5b04179958b/Licensing_Microsoft_Server_Products_in_Virtual_Environments.docx

This reads to me as follows (using an example for simplicity)

I am using a 2 guests, one of which is sql server.

The host has 2 cpus and 4 cores in each

My sql server guest is assigned 4 vcpus.

According to the article the 4 vcpus are considered as a single processor as the physical processor has 4 cores and therefore only 1 sql server licence.

(Obviously any extra guests containing sql server would need additional licensing)

dmc-608719 SSCarpal Tunnel Points: 4663 More actions · Answer 5

Late post here.. but interesting fact to consider is that you can also take the VM and make it see the 4 vCPUs as one cpu with 4 cores via a change to configuration file. This would allow you then to present back to the vm as single processor again.