Trying to correctly understand core licensing in a vmware environment
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I am trying to make sure I correctly understand core licensing in a virtual environment. At first, I had the assumption that I would only have to license the number of cores used by the VM -- so if I set it to use 2 vCPU with 8 cores each, then I could use the minimum standard licensing to cover the server even if the host it was running on had far more cores. After much reading, I see now that this is not the case, but I'm still not 100% clear on everything.
Let's say I'm running vSphere with 3 ESXi hosts in a cluster for fail-over and load balancing. My Server 2016 vm will only ever be running on ONE of them at any given time. However, I am seeing now that I still need to license ALL of the physical cores in all three of my hosts. Is this correct?
Details:
Host 1: 2 Processors, 4 cores each
Host 2: 2 Processors, 4 cores each
Host 3: 2 Processors, 10 cores eachTotal Cores = 36
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So if I want to have ONE single Server 2016 running and properly licensed, I would need to purchase 3 standard licenses (which would cover 48 cores) since it's required minimum of 8 cores per processor and 16 cores per server.
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After purchasing those 3 standard licenses to cover my 36 physical cores, I will now be able to run up to TWO Server 2016 machines on my cluster.
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If I want to run a 3rd or 4th Server 2016 vm, I would have to fully license all ESXi hosts again. Then I get two more instances of Server 2016.
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So if I wanted to eventually have 8 Server 2016 instances, I will need to license each host three times (or 9 Standard licenses) in order to be in compliance. Purchasing 9 standard licenses covers 144 cores which would leave me enough left over to cover 8 instances of Server 2016.
Is this all correct?
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@dave247 said in Trying to correctly understand core licensing in a vmware environment:
Let's say I'm running vSphere with 3 ESXi hosts in a cluster for fail-over and load balancing. My Server 2016 vm will only ever be running on ONE of them at any given time. However, I am seeing now that I still need to license ALL of the physical cores in all three of my hosts. Is this correct?
Details:
Host 1: 2 Processors, 4 cores each
Host 2: 2 Processors, 4 cores each
Host 3: 2 Processors, 10 cores each
Total Cores = 36Yes.
Do you have software assurance?
https://www.timothygruber.com/windows-server-2016/windows-server-2016-licensing-simplified/You need to buy:
Host 1 = 8x 2-core packs
Host 2 = 8x 2-core packs
Host 3 = 10x 2-core packsIt's 16 cores need licensed minimum per server. The third server is 20 cores, so you need two extra 2-core packs.
Unless you are running Windows Server Datacenter Edition, you need to purchase the above for every two VMs you run.
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You're looking at around $5k for every 2 VMs you want to run on that cluster in Windows Server Licensing, not to mention the cost of VMWare.
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@dave247 said in Trying to correctly understand core licensing in a vmware environment:
I am trying to make sure I correctly understand core licensing in a virtual environment. At first, I had the assumption that I would only have to license the number of cores used by the VM -- so if I set it to use 2 vCPU with 8 cores each, then I could use the minimum standard licensing to cover the server even if the host it was running on had far more cores. After much reading, I see now that this is not the case, but I'm still not 100% clear on everything.
Correct, it is the number of cores present on the server. Virtualization, and the choice of hypervisor, and the settings of the hypervisor or the VMs within it are not factors.
Important to note as it isn't said in the title, thisi s "Windows Core Licensing" specifically, for Windows servers.
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@dave247 said in Trying to correctly understand core licensing in a vmware environment:
Let's say I'm running vSphere with 3 ESXi hosts in a cluster for fail-over and load balancing. My Server 2016 vm will only ever be running on ONE of them at any given time. However, I am seeing now that I still need to license ALL of the physical cores in all three of my hosts. Is this correct?
That is correct. "At one time" isn't a factor in the licensing. If you had three hosts in a cluster, and the workload was pinned to one and could not move, you only need to license that one. If you allow it to move between the hosts, then you need to license all of the hosts.
This is not related to core licensing (which only changes what you count from CPUs to cores, that's literally the only change) but to broader Windows Server licensing as it has been for decades, both physical and virtual.
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@dave247 said in Trying to correctly understand core licensing in a vmware environment:
Details:
Host 1: 2 Processors, 4 cores each
Host 2: 2 Processors, 4 cores each
Host 3: 2 Processors, 10 cores eachTotal Cores = 36
Licensing is by server, never by cluster. There is no time when talking about licensing that you add up cores in this way. You couldn't do this with CPU licensing under 2012 or 2008, you can't do it with cores now. Remember, cores changes only one thing - that you count the cores instead of counting the CPUs. Nothing gets complex or weird, it stays the identical simply model it's been.
So you have:
Host 1: <16 cores, so you need 16 cores licensed.
Host 2: <16 cores, so you need 16 cores licensed.
Host 3: >16 cores, so you need 20 cores licensed.Don't think about it as a "cluster" while licensing, the licensing piece is cluster agnostic.
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@obsolesce said in Trying to correctly understand core licensing in a vmware environment:
You're looking at around $5k for every 2 VMs you want to run on that cluster in Windows Server Licensing, not to mention the cost of VMWare.
Which means for 9 VMs, that is $25K - $30K in software licensing alone. Moving to Hyper-V or KVM would save some, but most of it is Windows.
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@scottalanmiller said in Trying to correctly understand core licensing in a vmware environment:
Moving to Hyper-V or KVM would save some, but most of it is Windows
Isn't the bare minimum VMWare cost like $1300 per Cpu socket?
That's still $8k or so. And that doesn't get you anything more than Hyper-V except $8k of support you won't use.
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@obsolesce said in Trying to correctly understand core licensing in a vmware environment:
@scottalanmiller said in Trying to correctly understand core licensing in a vmware environment:
Moving to Hyper-V or KVM would save some, but most of it is Windows
Isn't the bare minimum VMWare cost like $1300 per Cpu socket?
That's still $8k or so. And that doesn't get you anything more than Hyper-V except $8k of support you won't use.
Roughly, yeah. It's crazy high. Basically outside of enterprise licensing where it is much cheaper and you are using crazy high end features, it just makes no sense to even consider. The cost is absurd. And so many limitations, like all of this licensing has to change just to go to a fourth host.
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So we're at like $35,000 of software licensing at this point... For what? What's the end goal here that justifies the costs? Oh, that's not even considering CALs. That could be many more thousands. And this is every few years without SA.
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VMWare also causes bizarre decision making because they get SMBs with their sunk cost fallacy because they sell you three hosts / six sockets as a minimum pack. So to "make use of what they bought", everyone then deploys exactly that.
But that isn't a useful number for modern SMBs, and it really screws you with Windows licensing and hardware costs.
Look at the example here, three tiny hosts (I know it's just a theoretical learning example, but it's how people do it) with six CPUs where three would be cheaper and have better performance, and three hosts where two would be cheaper and have better performance.
Look at the cluster size, it's a total of 36 cores. You can do that better and cheaper using two, single socket servers with 18 cores each! If you needed a little extra during a failover, go for two at 20 cores each or whatever.
It would drop something like 25-30% of the cost of the Windows licensing, and drop something like 15-25% of the hardware costs, all while reducing the number of things to fail (decent increase in reliability), giving you better sizing options on workloads (single critical workloads could be bigger), reducing the number of things to manage, and improving performance (better cache hits, memory performance, CPU performance!)
So many wins all lost, typically, because of nothing but a bizarre emotional reaction to the VMware licensing model.
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@obsolesce said in Trying to correctly understand core licensing in a vmware environment:
Oh, that's not even considering CALs. That could be many more thousands. And this is every few years without SA.
Yes, but the CALs aren't affected by the virtualization, the VMware, the cores, or the number of VMs. Only "at least one" Windows vs. "none at all."
If you could REALLY eliminate Windows completely, well then heck yeah, run those numbers. But realistically, the CALs are a given and don't change.
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@scottalanmiller said in Trying to correctly understand core licensing in a vmware environment:
@obsolesce said in Trying to correctly understand core licensing in a vmware environment:
Oh, that's not even considering CALs. That could be many more thousands. And this is every few years without SA.
Yes, but the CALs aren't affected by the virtualization, the VMware, the cores, or the number of VMs. Only "at least one" Windows vs. "none at all."
If you could REALLY eliminate Windows completely, well then heck yeah, run those numbers. But realistically, the CALs are a given and don't change.
I was assuming no up to date CALs in the environment for 2016.
But yeah, completely separate from the cluster and virtualization stuff.
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@obsolesce said in Trying to correctly understand core licensing in a vmware environment:
Unless you are running Windows Server Datacenter Edition, you need to purchase the above for every two VMs you run.
And the number on that is 13. If you need 12 VMs, you use Standard. If you need or anticipate 13+ soon, then you go datacenter. It's a simple determination.
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@dave247 said in Trying to correctly understand core licensing in a vmware environment:
- So if I want to have ONE single Server 2016 running and properly licensed, I would need to purchase 3 standard licenses (which would cover 48 cores) since it's required minimum of 8 cores per processor and 16 cores per server.
No, 52. 16 + 16 + 20 = 52.
This is assuming VM mobility in the cluster.
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@dave247 said in Trying to correctly understand core licensing in a vmware environment:
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After purchasing those 3 standard licenses to cover my 36 physical cores, I will now be able to run up to TWO Server 2016 machines on my cluster.
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If I want to run a 3rd or 4th Server 2016 vm, I would have to fully license all ESXi hosts again. Then I get two more instances of Server 2016.
Correct.
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@dave247 said in Trying to correctly understand core licensing in a vmware environment:
- So if I wanted to eventually have 8 Server 2016 instances, I will need to license each host three times (or 9 Standard licenses) in order to be in compliance. Purchasing 9 standard licenses covers 144 cores which would leave me enough left over to cover 8 instances of Server 2016.
Correct on the 9. But it is 156 cores, not 144.
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@obsolesce said in Trying to correctly understand core licensing in a vmware environment:
You're looking at around $5k for every 2 VMs you want to run on that cluster in Windows Server Licensing, not to mention the cost of VMWare.
Wait, how did you get $5k? Each license is $883, so for 3 hosts, that is like $2,650 for 2 vm's...
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@dave247 said in Trying to correctly understand core licensing in a vmware environment:
@obsolesce said in Trying to correctly understand core licensing in a vmware environment:
You're looking at around $5k for every 2 VMs you want to run on that cluster in Windows Server Licensing, not to mention the cost of VMWare.
Wait, how did you get $5k? Each license is $883, so for 3 hosts, that is like $2,650 for 2 vm's...
That does sound more logical. $5K sounded really high.
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Now to make things more complicated, if you didn't want cluster mobility, but only failover, you can move to SA licensing which isn't cheap, but is way cheaper than this. But if you wanted that, the three node cluster doesn't make sense. So based on the example, SA doesn't cover the goals.
