Linux On System Z - Pricing and Costs

Pricing and Costs

Linux on System z is not appropriate for small businesses that would have fewer than about 10 distributed Linux servers, although some expensive per-processor licensed software can quickly reduce that rule of thumb. Most software vendors, including IBM, treat the highly virtualized IFLs just like non-virtualized processors on other platforms for licensing purposes. In other words, a single IFL running scores of Linux instances still counts as one "ordinary" CPU, at the same CPU price, for software licensing. Test, development, quality assurance, training, and redundant production server instances can all run on one IFL (or more IFLs, but only if needed for peak demand performance capacity). Thus, beyond some minimum threshold, Linux on System z can quickly become cost-advantageous when factoring in labor and software costs.

The cost equation for Linux on System z is not always well understood and is controversial, and many businesses and governments have difficulty measuring, much less basing decisions on, software, labor, and other costs (such as the costs of outage and security breaches). Acquisition costs are often more visible, and small, non-scalable servers are "cheap." Nonetheless, non-acquisition costs are no less real and are usually far greater than hardware acquisition prices. Also, individual users and departments within larger businesses and governments sometimes have difficulty sharing computing infrastructure (or any other resources, for that matter), citing a loss of control. Server centralization, as Linux on System z provides, might reward cooperation with better service and lower costs, but that's not to say that cooperation is always easily accomplished within a corporate bureaucracy.

Linux on System z also supports less expensive disk storage devices than z/OS because Linux does not require FICON or ESCON attachment, although z/OS may use disk space more efficiently due to hardware-assisted database compression on z/OS. This compression effect is somewhat variable and may be somewhat reduced due to the minimum space allocation requirements for z/OS data sets (a full disk track).