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Program temporary fix

From Alfawiki
IBM
IndustryInformation technology
ProductsSoftware maintenance, bug fixes (PTFs)

In IBM's framework, a program temporary fix or product temporary fix (PTF) consists of one or more bug corrections packaged for immediate installation. Usually, a PTF is issued after an Authorized Program Analysis Report (APAR), which is an official notification from IBM development teams addressing a reported issue or defect. When an "APAR fix" is released, the PTF embodies a validated APAR or a collection of APAR fixes. Nevertheless, certain APARs classified as "Fixed If Next" or "Permanent Restriction" might not have a corresponding PTF and instead are resolved in subsequent product versions.

PTF installation

Originally, applying PTFs involved a partially manual procedure. Over time, IBM introduced tools such as IMAPTFLE and utilities like IEBEDIT to facilitate batch processing of PTF installations. For OS/360 and successors, this process evolved into the System Modification Program (SMP) and later the System Modification Program/Extended (SMP/E), which improved maintenance workflows significantly.

For the VM environment, PTF handling progressed through enhancements like Virtual Machine Serviceability Enhancements Staged (VM/SP SES) and VMSES/E. In the case of DOS/360 and successors, IBM developed the Maintain System History Program (MSHP) to aid in service management tasks.

PTF usage

Historically, PTFs were delivered monthly via Program Update Tape (PUT) or as part of Recommended Service Upgrade (RSU) bundles; however, they are now accessible for direct download through IBM support channels. Occasionally, IBM issues a "Cumulative PTF Pack," which is a comprehensive collection of interrelated fixes distributed on compact discs for straightforward system application.

Despite digital distribution advances, physical media remain necessary due to storage limitations. For instance, the default /home file system on VIOS for System p platforms offers only 10GB of space. Transferring large ISO files via FTP—such as those around 17GB—can surpass available capacity.

Within z/OS, applying PTFs through SMP/E involves multiple phases spanning several weeks. Each PTF may contain HOLDDATA, designating it as an exception SYSMOD. Typically, all available service is installed unless excluded by policy or HOLDDATA restrictions. A standard service cycle includes:

  1. Retrieving the latest HOLDDATA
  2. RECEIVE of service and HOLDDATA into the Consolidated Software Inventory (CSI)
  3. Running APPLY CHECK to detect exception SYSMODs, confirm prerequisite compliance, and identify potential issues
    1. Examining exception SYSMODs for required interventions or holds
    2. Updating documentation and implementing necessary measures
    3. Ordering and RECEIVING any missing prerequisites
    4. Restoring, rejecting, or reapplying local modifications impacted by the service
  4. Applying the service on a test system within a cluster environment and monitoring over several weeks
    1. Selectively BYPASSing HOLDDATA constraints when justified
  5. Performing RECEIVE and APPLY on production systems followed by observation of outcomes

Should complications occur, administrators can selectively RESTORE the applied service and engage IBM support resources. Once stability is confirmed, the service is permanently integrated by ACCEPTing it.

These corrective updates primarily address customer-reported APARs and serve as an initial resolution step before comprehensive fixes are incorporated into future product releases.

Comparison with APAR

When problems occur with IBM software, they frequently result from misconfigurations, issues with third-party hardware or software, or occasionally a defect within the IBM product itself. Once third-party hardware, external software, and user setup errors have been excluded, IBM support may initiate an Authorized Program Analysis Report (APAR) if a flaw in an IBM software release is detected.

APARs outline existing workarounds, indicate whether an official correction is planned for upcoming versions, and specify if a Program Temporary Fix (PTF) has been arranged.

Summary

Fixes are generally categorized into two primary types:

  • An APAR fix, designed to provide a rapid solution to the issue.
  • A permanent remedy known as a PTF, which is a validated APAR that fully resolves the problem.

While an APAR formally documents the issue until it is addressed, the PTF implements the fix permanently within the system.

Humor

Clients occasionally humorously call a PTF a permanent temporary fix or probably this fixes, highlighting its nature as a patch that may become lasting if successful. Another lighthearted description refers to a PTF as temporary "just until the next ice age."

See also

External links

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