vSphere 5 vRAM Licensing

The new licensing scheme is used in vSphere 5. Unlike in vSphere 4, where vRAM is not taken into consideration rather the number of cores per socket.

Let do a refresh. In vSphere 4, for Enterprise edition is entitled to 6 cores per physical processor per server. For Advanced/Enterprise Plus edition, is entitled to 12 cores per physical processor.

An example would be follows:
1 server with 2 physical CPU, each with 8 cores. This will require 2 x Enterprise Plus license.
If you apply 2 x Enterprise instead of Enterprise Plus license, only 6 cores per CPU will be used and 2 cores per CPU left idle.

Let’s talk about vSphere 5 licensing. Before we begin, vSphere 5 have removed Advanced edition. An customers who are on Advanced Edition on vSphere 4 will be upgrade to vSphere 5 Enterprise.

vRAM entitlement that is based on edition per physical CPU (no more limitation of number of cores). Its base on vRAM allocated. So what is vRAM different from physical RAM?

vRAM actually define the virtual memory that is allocated to any VM that is powered on. But there are misconception here that most customer have.

Consideration 1:
If you have a server with 128GB of RAM with 2 physical CPU, do I purchase 128GB of vRAM? The answer is No. In a normal setup, we often leave buffer of resource for HA or DRS in such this buffer does not have to take into considerations. Since allocated memory to a VM remain the same when HA or DRS kicked in you are not using twice as much the vRAM.

Consideration 2:
What if I need to increase the allocated vRAM to a VM once awhile? VMware will only use the average vRAM allocation per year. In such, occasional increase or even creation of a VM for testing for a short period and later destroyed or power off will not bridge your entitlement as long in average/year allocation does not exceed. This is possible as the license does not have a hard restriction on the server even though you do not have enough vRAM entitlement you are still able to allocate more than you have.

When planning your license, you do have to take note of the vRAM required minus the buffer used for HA where e..g N+1 is used. Of cause you can always buy additional license in the future when needed as well.

If HA was to kicked in when one host were to fail, the entitlement on the failed host will be available and shared by the remaining hosts. I.E to say the total vRAM entitlement will be pool together and shared within the cluster. Provided that the editions are the same.

Taking the same example of the physical server as above:

1 server with 2 physical CPUs (cores is not a concern), 128GB physical RAM.
Since there are 2 physical CPUs, you would need 2 x any edition license.
Then we will take note of the vRAM now.
If you are on Essential Plus license, you will be need 2 x Essential Plus which entitles you to 32×2=64GB vRAM.

Say you intend to have 100GB of vRAM for use taking consideration for furture VMs and leaving 28GB as buffer. We will be short of 36GB. Then you will need to get 2 x Essential Plus license to top up as 2x32GB is only 64GB of vRAM.

Say you are into Enterprise license, you will still need 2 x Enterprise = 96 x 2=192GB of vRAM. In such, you have more than enough. In such, you can even increase the physical RAM without purchasing additional vRAM license.

Consideration 3:
Now you may ask why do I have to buy so many Essential+ from the example above? Can I just buy another edition to top up? The answer is No and not a recommended practice. If a host is entitled to a different edition, the entitlement cannot be shared. In such, the host that is assigned to the different edition license will be standalone.

Consideration 4:
What if I have a VM that requires more than 96GB of vRAM that Enterprise Plus entitles?
If you are on Enterprise Plus, the VM can be allocate more than 96GB of vRAM without any penalty. Its 96GB or above.

Consideration 5:
What if you are using View won’t I have to purchase lots of license?
Answer is No. For View, vRAM is unlimited license. It will be Desktop license which has unlimited vRAM entitlement.

IMPORTANT: Due to the different licensing entitlement for vRAM for Desktop and infrastructure, it is strongly recommended not to mixed both environments together.

I have the table of the license entitlement below:

vSphere Edition

vRAM Entitlement/CPU

vSphere Enterprise Plus 96 GB
vSphere Enterprise 64 GB
vSphere Standard 32 GB
vSphere Essentials Plus 32 GB
vSphere Essentials 32 GB
vSphere Hypervisor Free Edition 32 GB
vSphere Desktop Unlimited

Thanks to : Tanweekiong.blogspot.com

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