VMware added over 130 new features to the next version of their flagship hypervisor, vSphere 5. Due to be released in Q3 of 2011, vSphere 5 will see the next step in the evolution of virtualization, enabling a number of new technologies and providing a solid infrastructure for cloud computing. Along with improved features, VMware is also introducing a new licensing model meant to prepare vSphere for the future.
Processors are changing. VMware has acknowledged that the current emphasis on licensing by processor, with restrictions on the number of cores, will not match up to where CPU capabilities are going. With vSphere 4, CPU licenses had core limitations that varied between either 6 cores or 12 cores, based on edition.
Processors with 8 and 12 cores are becoming more common, and will soon be the standard. To accomodate this, VMware has removed all limitations based on processor cores from its vSphere 5 licensing model. However, as new servers with two twelve core processors and high memory capacities become more common, VMware has placed a new emphasis on memory in its licensing model. To be specific, virtual memory is allocated to a running virtual machine.
Let’s first break down the licensing models for vSphere 4 and vSphere 5, then review a few possible scenarios:
|
|
||||||||||||||||||||||
|
|||||||||||||||||||||||
|
|||||||||||||||||||||||
|
|||||||||||||||||||||||
|
|||||||||||||||||||||||
|
Summary:
There are now two factors to consider in determining license needs. First, determine licensing needs based on physical CPU count. Then assess the total vRAM allocation across all VMs within your environment (which may span multiple locations if using linked vCenter servers). Your license count will need to be sized to cover both of those numbers.
One option to consider is leveraging unused vRAM capacity from environments that may traditionally not consume high levels of vRAM. These could include environments hosting Unified Communications deployments or even disaster recovery environments. Simply use the linked vCenter feature to combine all of these licenses into a common pool. I have always recommended organizations link all of their vCenter servers together, for the many administrative advantages this configuration provides. However, with the new licensing model, such a configuration can also provide for better license utilization.
In terms of availability and agility, it is also important to note that vRAM limits are “soft” limits that are monitored and alerted on, but will not actually prevent a virtual machine from being powered on. You are bound by your End User License Agreement to comply with these license limits, but VMware has chosen to monitor based on this metric and not actually impose hard limits that may negatively impact your ability to respond to business demands.
Related links:
http://www.vmware.com/files/pdf/vsphere_pricing.pdf
http://www.virtu-al.net/2011/07/14/vsphere-5-license-entitlements/