Linux For S/390 And The Virtual Server Concepts

This concluding article discusses the business case for a Linux on S/390 implementation. Historically, the justification for workstation and mini-computer class systems has been based solely on the discussion of acquisition price for the base hardware; only a few years ago a simple upgrade, such as a 64MB memory upgrade for a medium-range S/390 processor, could easily have cost more than $50,000 USD. Today, given IBM's efforts at reengineering the S/390 to use commodity parts without sacrificing the system's legendary reliability and self-management features, it is more difficult to justify the financial case for workstation-based computing vs. centralized large system computing. A more sophisticated analysis is necessary; one needs to consider not just the hardware, but also the cost of operating and maintaining the facilities and communications infrastructure required, the staffing required to deploy, maintain, and operate the environment, and the time required to deliver a solution to the marketplace.

In the case presented here, an additional element is added that represents a significant competitive advantage in today's market place: time-to-market. This term reflects the speed at which a service can be set up, configured, managed, and billed (note that billing is a critical point -- in most cases we are not operating charities) to a specific customer. The time-to-market depends on a number of different elements, including time to purchase, mount, and configure the system for its initial purpose; integration of the server into its management infrastructure; setting and programming any triggers or other alerting functions; and delivery of necessary access information to the customer in a timely manner. In most cases, large, established hosting providers have delivery times averaging five to seven days -- some larger providers have used economies of scale and onsite inventory to reduce this time to three to four days at the cost of maintaining a stock of equipment subject to depreciation and aging. Time-to-market is a deciding factor for most ISP and IDC customers -- it represents how quickly they can deliver information content to their potential customers; a matter of hours can make the difference between catching or missing a new trend or providing additional capacity in a crunch vs. failing to meet customers' needs. Empirically, customers often opt for services that can be deployed quickly over lower price, relying on the "first with the most" strategy to offset the financial impact. To borrow a phrase from a Cisco staffer, "The competition is only a click away."

Compare Facilities Cost

To build on that idea, we turn next to the largest portion of the cost: facilities. Costs of facilities include a large number of elements, but can be broken down into three major categories:
environmental costs - such as floor space, power, air-conditioning, cabling, and rack space deployment costs - such as the time required to build the system to order, or to ensure deployment in a supportable environment management costs - which include the cost of operating the server in terms of maintenance, capacity planning, system command and control infrastructure It's important to consider all three elements in the analysis, as they tend to be difficult to quantify in absolute terms due to a general industry-wide lack of experience in operational management techniques.

Commercial vs. Open Source Applications?

Turning from operational requirements, we need to also explore the relatively slow adoption of Linux (on any platform) by the commercial software vendors. While in the ISP and IDC industry, this is less likely to be an issue, as most Internet services and utilities are already based on open source tools, this can be a drawback to the Linux-based solution. In our ISP case, the applications used (bind, the standard Unix Internet domain name server, and INN, the standard Usenet News server software) were already open source. There are additional examples of business-oriented tools such as the PostgreSQL database or the Apache WWW server that are certainly ready for production use.

Fortunately, the advent of Linux for the S/390 has prodded a number of large vendors such as Software AG, BMC Software, and IBM itself, to announce enterprise middle-ware such as MQSeries, BMC Patrol, DB2, and Tamino for Linux on a number of platforms.
Consider also that the richness of the open source community has produced some commercial-quality tools and capabilities that may in some cases provide an auxiliary source or replacement for an expensive commercial application. As an additional bonus, defect remedy tends to move much faster in the open source community than in the proprietary software world: serious flaws in sendmail or the Linux kernel, for example, are typically fixed in a matter of hours rather than days or weeks. Each environment has differing requirements, but in the cost case, you may be able to gain a substantial savings by using open source applications in some portions of the environment.

SELLING A LINUX SOLUTION TO MANAGEMENT

At times, the best rational case and decision doesn't make the case airtight for management to appreciate yet move beyond what seems to be "common" wisdom. To get the case across to a manager, often there are two types of justifications that need to be made: a financially-oriented case focusing on cost savings and competitive advantage, and a technology-enabling case that focuses on the technical capabilities and additional possibilities the solution provides. In each case, the following considerations help generate the necessary elements to demonstrate the power of the solution.

Technical Case

The technical case might be more comfortable and easier to use for opening a persuasive argument. In our example, the technical focus revolved around the flexibility of the virtual system environment -- being able to create, destroy and reconfigure servers quickly, and to react equally quickly to customer capacity and software requirement demands. Use of open source applications allowed for fast response to customer problems and queries, and the level of automation possible in the virtual system environment provided a significant technical advantage to minimize operational complexity and increase the number of services available with minimal additional hardware.

Financial Case

Correspondingly, the financial case focused on the total cost of ownership and acquisition. As presented in the hardware section, the cost of each individual discrete server is quite a bit lower than the S/390. However, only one S/390 is required to replace 750 discrete servers, with substantial savings in environmentals and additional management infrastructure. We also demonstrated a much shorter time to market, which offers a significant competitive advantage to the operator by allowing both lower prices and higher availability to the customer.