Note: VMware vSphere 5 vRAM has dramatically been amended since the original announcement. For more info about what was amended then please check my following article: vSphere 5 vRam Licensing Amendment. Further, this article has been updated accordingly.
While others have decided to cover up all the nice features that is coming up with vSphere 5 & vCloud Director 1.5, I was quite busy explaining to customers that most of them are not affected by the new vSphere 5 vRAM Licensing Schema. Actually none of the existing customers who called me asking about the licensing change was near being affected by the new licensing schema. Let’s be honest when I first heard about the new licensing schema I had panicked too, but only few hours laters of research I have discovered it actually make sense and not as bad as it look at first glance.
I don’t blame our customers for not grabbing the idea of our new VMware vSphere 5 vRAM based licensing as it take to understand the new licensing model to read beyond the surface to find out how it really work. Therefore before you complain about it, please make sure if you are affected by reading the Understand the vSphere 5 vRAM Licensing Model. After that or before it you can read my below 7 reasons why the new VMware vSphere 5 vRAM Licensing is not as bad as it look at the first glance. Actually I start believing its a quite smart and a step forward toward Cloud Licensing model.
1- Most Customers will not be affected by VMware vSphere 5 vRAM Licensing:
Unlike what most customers think at first glance or as competitors try to convey the message to them, their licensing cost will not be affected for most. You will need to clearly understand how vRAM is calculated before judging if your licensing cost will be affected. Its an important first to note that vRAM has nothing to do with how much Physical RAM you install in an ESXi Server. Its actually calculated to be the sum of all powered on VMs RAM managed by a single vCenter or vCenters in Linked Mode, & that will be compared to all the vRAM entitled by all of your ESXi Servers licenses that you have obtained.
Let’s take a small example. If you have licensed 3 vSphere 5 ESXi hosts (2 CPUs per host) using vSphere Enterprise Plus (Which entitle you to 96GB vRAM per CPU) that will entitle you to 96 * 6CPU = 576 GB of vRAM. You will have to have concurrently running VMs with a total of over 576GB of RAM in this environment before your licensing cost is affected.Below are few spots where a lot of confusing will happen.
* Most people will think if they fit more than 576GB of RAM(The Amount of vRAM they are entitled to) in their servers they will have to pay extra & that is not true at all, as the new licensing schema does not look at how much RAM you fit in your hosts at all.
* A lot of people will think if they exceed the amount of vRAM on a certain ESXi host, they will in-occur additional cost. Again, this is not true as vRAM entitlement will be pooled across all the ESXi hosts and even if you exceed your entitlement per one/few host(s) you are more than likely will have some others where vRAM entitlement is not reached and will cover up for this host..
– I believe its important to point out how vRAM compare to physical RAM, as I mentioned earlier a lot of people confuse them. Although as mentioned earlier vRAM is calculated as a RAM pool of all servers entitlement in your environment I want to demonstrate an example where you will be utilizing much more physical RAM on a server than its entitled vRAM and still in compliance:
* First start with a host running vSphere Enterprise Plus with 2 CPU which will entitle you for 2 X 96GB/CPU = 192GB of vRAM.
* Second & which is very important to consider for most large environments which is normally the place where you will find large systems that can fit a large amount of memory, you will always have a disaster recover setup that is setting idle and only utilized in case of a Disaster. In this case & as long your vCenter in DR & Head Office are linked together you are entitled to utilize that sleeping vRAM in DR at your Active head office setup. So if you were doing a 1-to-1 DR and using Enterprise Plus at your DR you will be entitled for double the vRAM at your head office. In this case you will be entitled for 384GB of vRAM
* Third Let’s assume you utilize 16GB of RAM for over head so you still legally utilizing 400GB of physical RAM, as you don’t pay for overhead RAM.
* Fourth lets assume you will reserve 20% of each of your hosts RAM for HA, then you will need an additional 20% physical RAM to accommodate for HA which will get you to utilize 480GB of Physical RAM for this server without breaking your license yet as you don’t calculate RAM reserved to accommodate for HA in your vRAM usage.
Note: The idea of this example just to show how vRAM work and how you can still utilize massive systems with a huge amount of RAM in many cases without having to pay any additional fees. As well it show how vRAM is not related to how much physical RAM you install into each server
2- Desktop Virtualization is not affected by VMware vSphere 5 vRAM licensing:
The most common use of vSphere scale up design with tons of RAM per server is in Desktop Virtualization. Actually its the only place it has been recommended for. vSphere 5 vRAM licensing could had a bad affect on the cost of Desktop Virtualization as vRAM would have been easily exceeded in these situations. For that VMware has excluded hosts utilized for VMware View or Third Party VDI Solutions when dedicated only for VDI from the vRAM Licensing Schema. That means you can utilize as much vRAM you desire on ESXi server utilized for VMware View/Third Party VDI without having to worry about it. Further with vSphere being the most popular platform to run Desktop Virtualization on even for third party connection brokers (Ex: Citrix XenDesktop), VMware has excluded these implementations as well from the vRAM licensing Schema and released a special licensing schema for it which is known by vSphere Desktop. More info can be found at: vSphere Desktop Licensing Overview. There is a lot of FUD out there that if you have existing vSphere 4 and using it for third party VDI, that you will have to replace it with vSphere Desktop at an Extra cost to benefit of vRAM exemption. That is not true. You can upgrade your ESXi host to vSphere 5 and as long you are only using them for VDI you don’t have to worry about vRAM.
3- Virtual Licensing has gone Virtual.
The new VMware vSphere 5 licensing Schema has removed two physical constrains that existed in vSphere 4 and replaced them with a virtual constrain called vRAM (Explained earlier in this article). The two physical constrains that was removed were the number of cores per CPU & the amount of memory supported per host. In vSphere 4 the number of cores per CPU supported in Standard/Enterprise Edition was 6 & for Advanced & Enterprise plus it was 12 cores per CPU. This number of cores per CPU constraint has forced a lot of customers to stick to a higher Editions of vSphere in order for it to support the number of cores they have on their newly purchased hardware. Although the RAM limitation of 256GB per host in all vSphere 4 Edition beside the Enterprise Plus one was not a big issue for most, it was still a physical limitation that some customers wanted to get rid of. The good news is that the new vSphere 5 licensing Schema has got rid of both of these physical licensing constrains and replaced them with a virtual one (vRAM) just the way it should be.
4- The Opportunity to buy the Hardware you like with the Specs you like.
As all the hardware constrains have been removed, you never have to worry any more by how many cores or how much RAM is fitted in a server. This gives you the option to look at a wider range of servers configuration and probably give you the chance to opt for a better configuration for a lower price without having to affect your vSphere 5 Licensing.(Did some one say he wanted more cores/cpu in vSphere 4 Standard Edition?)
5- A step forward toward a Cloud Computing Licensing Model.
The more we move toward Cloud Computing the more VMware have to flip its pricing model into a similar pricing method to the utility companies (Per Usage pricing). I believe introducing vRAM and removing Cores/CPU & RAM/host limitation is just one step further into that model. I mean look how would it work out if VMware actually remove the number of CPU sockets in the future and only price things per vRAM so you will only pay per what you use. I am not saying that is where VMware licensing is going as I have no road map what so ever on that, but hey that seems kinda logical way to price when talking about Cloud Computing.
6- Enforce Best Practice Scale Out Design for Server Virtualization.
For long time Scale Out has always been the recommended Design for Server Virtualization for two reasons:
* Avoid the long downtime for HA or equivalent feature to bring all the failing VMs on a massive host up again after a host failure.
* Reduce the affect of a single Server Failure.
Although that has been always recommended to customers, the new schema will take one step forward to encourage customers & get them rewarded for using a scale out design.
7- Enforce customers to take a better care of sizing their VMs
In many environments today, VMs have been provisioned in the same way if the customer would have bought a physical server. If they used to buy servers with 16GB of RAM although they only never exceeded the usage of 2GB, then they will still provision a VM with 16GB of RAM. Over-Provisioned VMs have always been a problem in Virtualized environment as it kill resources for no reason as well reduce the performance of the host over all. The new Schema will make admins have a better care of properly sizing VMs which will eventually raise the importance of tools like VKernel Capacity Analyzer & VMware vCenter CapacityIQ
Last Note: To figure out if you will be affected by the new vSphere 5 Licensing & vRAM you can utilize the following VMware tool to study your vSphere 4 environment and report to you your vRAM utilization. Have a look at the utility here
Thanks for all who contributing by leaving comments and feedback, as in response to that the entitlment has dramatically increased and other improvement were introduced to the vSphere 5 vRAM licensing Schema. For more info on that you can check the following article: vSphere 5 vRam Licensing Amendment.
I hope this help explain it, & please leave your additional opinion & feedback in the comments area below.