Servicing z/VM

This topic introduces IBM® service concepts.

After this introduction, turn to Installing preventive or corrective service in z/VM: Service Guide to install z/VM service.

z/VM service concepts

A component of z/VM called VMSES/E helps you install z/VM and other VMSES/E-enabled products and apply service changes that correct or circumvent reported problems. VMSES/E handles both source code and binaries.

Service is the process of changing a particular release of a software product. There are a number of reasons for servicing a product, such as:
  • Correcting a problem. Problems that you report to IBM are first entered into problem management records (PMRs). If IBM determines that a PMR requires a fix to a product, IBM creates a record called an authorized program analysis report (APAR). APARs provide a formal method of tracking problems for a specific version of a product. An APAR can also affect several releases of a product. IBM fixes these problems for a particular release through program temporary fixes (PTFs). A PTF contains the code changes for a solution to a problem (APAR) on a particular release. Each release of a product has a unique set of PTFs, because the fixes may be different on each release. When IBM ships a new release of a product like z/VM, PTFs from the previous release are merged into the new release.
  • Adding function. New functions can be delivered in a new release or version of a product, or as service. When new function is delivered as service, it is called a small programming enhancement (SPE). SPEs are delivered and tracked the same way as problems. An APAR is assigned to the SPE, and it is delivered as a program temporary fix (PTF).
    IBM delivers service through:
    • Recommended service upgrade (RSU) tapes, electronic envelopes, or CD-ROMs, which contain a collection of PTFs that IBM thinks are important enough that everyone should apply them. An RSU defines a service level for your product and is designed to prevent problems from occurring. (VMSES/E creates a software inventory and tracks the currency of the system through service levels.) This type of service is called preventive service.
    • Corrective service (COR) tapes, electronic envelopes, or CD-ROMs, which contain PTFs that you request for a specific problem. Sometimes you cannot wait for an RSU to correct a problem, so you can order a PTF through a COR. This type of service is called corrective service because it is designed to correct a specific problem you encountered with the product.
    • Expanded Service Options (ESOs), which are defined collections of PTFs delivered in VMSES/E corrective service format. ESO allows you to choose the starting and ending service levels.

      A product can have either an RSU or an ESO, but not both.

    Other reasons for changing a product are:

  • Circumventing a problem. For expediency, IBM may provide a circumvention for a problem until a PTF can be developed. A circumvention is meant to be a temporary solution to the problem, and it may be in the form of a procedural or software change. The method of delivery depends on the form of the solution, and it is determined by you and the IBM support center. Once an APAR number is established for the problem, you can use that number to track the fix and see when a PTF is available.
  • Applying local service or modifications. Local service and local modifications are defined as any service or software change that is applied to your z/VM system that was not supplied by IBM through corrective service (COR) or a recommended service upgrade (RSU).

    When it is absolutely necessary to apply service from IBM before it is available on a COR tape, or when you need a local modification to tailor your system environment, you must apply the service locally. Local service includes updates supplied to you by other vendors or Licensed Products. Note that as subsequent PTFs are installed, both circumventions and local modifications may require rework.

    For more information on adding local modifications, see Applying local service and local modifications in z/VM: Service Guide.

In general, then:
  • Someone reports a problem to IBM, which is entered as a problem management record (PMR).
  • If it determines that a fix is needed, IBM creates an authorized program analysis report (APAR) for the code defect (bug).
  • The solution for an APAR is a program temporary fix (PTF), which is like a code patch. The PTF might provide source updates in addition to new binaries.
  • The PTF might be delivered as preventive service on a recommended service upgrade (RSU). RSUs are periodic and intended for everyone to apply as a way of preventing problems.
  • For problems you encounter that require immediate fixes, the PTF can be delivered by corrective service (COR).
  • Though PTFs usually contain fixes, sometimes IBM delivers new function through them, called small programming enhancements (SPEs).
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