In the past, when deploying IBM software licensed on a Processor Value Unit (PVU) basis on servers that are configured in clusters for fail-over or load-balancing reasons, it generally has been necessary to license all servers in the cluster for that product. (Read more here.) Thus, for example, though a business may only be deriving limited functionality from an installation of DB2 Enterprise on one server, if that server is in an 8-unit cluster where each of the physical servers is identical to the one where DB2 is installed, the IBM customer could incur a DB2 Enterprise licensing charge equal to 8 times the amount to license the single host machine. For many products (including DB2 Enterprise), this could result in multi-million dollar licensing bills.

However, in October 2011, IBM announced that “the full-capacity license requirement for servers within a cluster is [now] limited to the servers made available to the eligible products.” At first glance, this appears to be a significant reprieve for licensees that otherwise would be subject to the full-capacity clustering burden.

Unfortunately, nowhere in its licensing terms does IBM define what it means to make a server “available to” a software product. In some clustering arrangements, it is conceivable that the processor resources used in connection with a software product are resources that are provided solely by a single physical host in the cluster. However, this would largely defeat the purpose of clustering, which is increasingly popular because it results in the resources of multiple physical hosts being made available, either automatically or with user input, to processes triggered by software installed on other machines in the cluster. Thus, the ultimate value of the October 2011 announcement may be doubtful.

As with all issues affecting IBM licensing obligations, it makes sense for IT, procurement and legal teams to work in concert to analyze a company’s licensing needs and to configure the company’s systems to maximize its technological and financial resources.