Many users of the VMware Academic Software Licensing program ask us about how they can most effectively use vSphere in their classroom, especially given the limitations on license keys provided under the Licensing program. It helps to understand the purpose of the licensing program, and some examples of creative ways to use licenses follow.
The Software Licensing program was created to provide end users — primarily students — with access to VMware’s core products. Most directly that means students can download software for use on their own personal machines, either to enhance their day-to-day computing environment or to learn about VMware’s core enterprise-focused products. The program also supports the installation of VMware software on shared physical infrastructure, but only within certain parameters. Most specifically, the program’s primary purpose is NOT to support the deployment of shared infrastructure using free licenses, in part because the lack of support provided (or available) with licenses places an undue burden on local administrators.
Each student user of the Academic Software Licensing program is entitled to receive one license key per product per year, and users can renew license keys prior to their expiration. License keys for desktop products — Fusion, Workstation, and Player — can only be used on a single system, whereas infrastructure products — VMware vSphere — have a ‘capacity’ value associated with the license key, which entitles the user to enable up to that many physical CPUs (typically 4). The number of CPU cores is irrelevant, vSphere licensing is based upon physical CPUs in a server (sometimes referred to in order to reduce ambiguity as to the number of CPU sockets). The capacity of a single license key can be distributed across multiple hosts, e.g., a 4-CPU key can be used to enable two hosts, each with 2 CPUs.
These constraints on license keys mean that a single user can only create a very small vSphere system using their own license keys. While such a small system should still be sufficient for an individual to demonstrate and learn about all of the core concepts of VMware’s products, teachers may wish to build larger systems for use in the classroom. Although the program is unable to provide additional license keys directly to teachers and administrators for that purpose, there are various creative ways in which a classroom environment can be created and managed while conforming to the license agreement.
The core of the vSphere product is the ESXi hypervisor. ESXi is not installed as an application, onto an existing host operating system. Rather, it is deployed into a ‘bare metal’ environment, usually a physical server, and replaces any other OS on that system (dual booting is possible, but left as an exercise for the reader). Thus it is generally not practical to have students install ESXi onto their own laptops or other personal machines unless students have additional machines at their disposal that can be dedicated to a role as an ESXi host. Some classes do in fact provide each student, or group of students, with a physical server that is assigned to them for the duration of the class; another alternative is to configure a machine to boot ESXi from external media.
An alternative, possibly complementary, approach is to install ESXi into a VM running within one of VMware’s desktop (hosted) virtualization products: Fusion (for Mac OS X systems) or Workstation (for Windows PCs). While this typically imposes some additional virtualization overhead on the ESXi system it provides the user with a much greater degree of flexibility, and, most importantly, allows concurrent use of the standard desktop OS while ESXi is running. However, one caveat is that ESXi requires substantial resources in order to be installed: current versions require 2 CPU cores and 4GB of memory. The vCenter management server, which is typically required to manage ESXi, also requires at least 4GB to be usable, and thus a basic system of one ESXi host and one vCenter server requires 8GB of memory. Most current laptop environments do not provide sufficient physical memory to support that within a hosted environment.
Most of VMware’s products can be activated for a 30-60 day evaluation period. This allows administrators to deploy software to physical (or virtual) servers in advance of the distribution of license keys to those servers. Alternatively, some classes may include the installation of software on servers as the first hands-on step in the class. Subsequently, students access the VMAP Software Licensing portal and download license keys for particular products to be used in their class.
vSphere license keys can be deployed to hosts in two different ways: directly to the ESXi host itself, or managed collectively in the vCenter server. For a very small system, up to 4 physical CPUs, it may be sufficient for students to deploy a single license key per system, but in environments where teachers wish to demonstrate concepts using larger systems, the students should be assigned to teams that can combine their individual license keys. In that manner, a team of 2-4 students can collectively contribute sufficient license keys to enable 8-16 physical CPUs across multiple hosts.