Crossposting to pctech, all replies to pctech please :)
On Thu, Sep 3, 2009 at 22:08, Walden H. Leverich<WaldenL@xxxxxxxxxxxxxxx> wrote:
You can also license Windows on a per-socket instead of a per-instance
base,
Isn't that the default license? IOW, if I have a quad-socket quad-core
machine (16-way) I'm ok w/a non-multi-socket license IF I restrict the
VM to run on cores 0-3 (or 4-7, 8-11, 12-15) only.
No, the normal Windows licenses (Standard, Enterprise) are generally
licensed on a per-instance base, though there are some special rules
for virtualization.
A single Standard license offers up to 4 sockets and a single standard
license allows you to run
a) A physical instance
b) A physical instance dedicated to virtualization (e.G. Hyper-V or
VMware Server, which may not run any additional software) and one
virtual instance running on the aforementioned physical instance
c) A virtual instance using a Hypervisor (e.G. Hyper-V Server, VMware ESXi)
A single Enterprise license offers up to to 8 sockets and a single
enterprise license allows you to run
a) -> same as Standard
b) -> same as Standard, but up to four virtual instances
c) Up to four virtual instances using a Hypervisor (e.G. Hyper-V
Server, VMware ESXi)
Now, Datacenter Edition is licensed on a per-socket base. For example,
you need 4 Datacenter Edition licenses if you intend to run this on an
IBM x3850 M2, which is a four-socket machine . And this allows you to
run:
a) -> same as Standard
b) A physical instance with unlimited virtual instances
c) Unlimited virtual instances using a Hypervisor (e.G. Hyper-V
Server, VMware ESXi)
Datacenter is basically the only way to get licensing in a
meaningfully cheap way if you intend to use advanced VMware features
like DRS or Vmotion.
Imagine this scenario:
You have three ESXi hosts. Each of them runs 4 VMs. You bought 3x
Enterprise Edition, each Enterprise Edition is assigned to one of the
ESXi hosts. Now you take one of the ESXi hosts down for maintenance,
and Vmotion two VMs to each of the remaining hosts. You're now running
6 VMs on on each ESXi host, but they're not licensed to run 6 VMs -
only for four.
Another scenario is running Windows Standard on a 8 socket machine.
This is perfectly possible, but some considerations need to be taken
care off. For example, if you have 8 sockets each running a single
core CPU, you may only allocate 4 VCPUs to the Windows Standard
instance. If you however run 8 sockets with a dualcore CPU, 8 VCPUs
are allowed. The licensing depends on the amount of sockets, not of
cores - so for example if you had a 8 socket machine with 8 core CPUs,
you may use up to 4x8 VCPUs (which nothing supports yet) in a Standard
VM.
Sources:
http://www.microsoft.com/windowsserver2008/en/us/r2-compare-specs.aspx
http://www.microsoftvolumelicensing.com/userights/PUR.aspx
Hope this clears things up a bit - Windows licensing sucks.
midrange.com
