Many a times licensing of software are overlooked in virtualization infrastructure. Virtualization actually complicate the licensing, accordingly CIOs and System Administrators should have some strategy or exercise to make sure that the organization has redeem the correct software licensing.
There are varieties of issues that can make licensing difficult in virtualized environment. One of the most common licensing issues is buying or purchasing several different license types in order to remain compliant. Few of the required license types are:
- Hypervisor licenses,
- Management Server licenses,
- Managed server licenses,
- Guest OS Server licenses,
- Guest OS Client licenses,
- Application licenses,
- Application client licenses, etc.
A complicated licensing issue occurs when a Guest OS VM created on a host and immediately migrated to another host. In the same ways, new VMs can be created on a whim by anyone who has permissions. So, how CIOs and System Admins can keep up with the licensing requirements?
All the software vendors have their own unique way of licensing requirements. So it is CIO’s duty to make sure that you adhere to requirements of the software rather than following the set of guidelines. There are a few general strategies too that usually work.
Always pay attention socket-specific license requirements. It is common now that maximum of the hypervisor vendors base their licensing requirements as per-physical socket for hypervisor and management server.
If an Operating System vendor requires licensing for every user who accesses the server, that requirement doesn’t usually go away just because the server is running on virtual hardware. Whereas, vendors provide choices to purchase the client access licensing on either a per-user or per-device basis. Previously, companies use to purchase licensing on per-device basis, as that was a little less expensive. But today, with every user using multiple devices having user based licensing is a cost effective option.
If VMs are running free open source OS, otherwise the Guest OS on your VM must be licensed. Guest OS licensing policies vary widely so it is important to check with the vendor to examine the specific requirements.
Windows Server 2012 R2 licensing applies only to the host not on the VM. This host-level license applies to the VMs running on the host. For example: if an organization is running Windows Server 2012 R2 on VMware. Company obviously licenses the VMware Hypervisor, but company also has to purchase Windows Server License. This license will apply to the Windows VMs running on the VMware server. If a VM is migrated to a different VMware server, then the destination Windows Server licensed will apply to the VM. In other words, Windows Server VMs do not take their licensing with them while migrating from one host to another.
Virtualization management servers typically require licenses for each server that is being managed. For example if a company plan to use Microsoft System Center VMM (Virtual Machine Manager), then company will need a licenses for each host server they are planning to manage.
Mostly licensing is complicated in virtualized environments. CIOs should review the licensing periodically and make sure to check the requirements for library servers to ensure if there are any licenses required for software installed within an image that is used to create new VMs.