Single fixes

Single PTFs (fixes) are applied to correct specific reported problems.

A single fix is tested by IBM and is made available to all IBM® customers. Single fixes are capable of being downloaded with electronic customer support or from the Internet and might also be available on media. Single fixes can identify other single fixes as prerequisite, corequisite, technology refresh requisite, or distribution requisite fixes.

HIPER PTFs

A HIPER (High Impact PERvasive) PTF resolves a problem that might have a high impact on IBM i operations or a pervasive problem that affects most systems.

HIPER PTFs correct severe problems that occur on your system. HIPER PTFs represent two types of problems: high impact or pervasive and high impact and pervasive. Examples of these situations include the following:

Your system might crash or hang and require a restart or IPL (initial program load) to recover.
Your system might be stuck in a looping condition.
Your system's data integrity might be threatened.
Your system may experience a severe performance degradation, or the problem involves usability of a product's major function.

If any of the fixes are needed to address these situations for your system, order and install the HIPER fixes. To help you manage HIPER fixes, IBM maintains a HIPER PTF group that contains a list of all current HIPER fixes for each supported IBM i release. For a complete listing of HIPER fixes, see the preventive service planning information at the Support for IBM i Link outside information center Web site.

Technology refresh PTFs

A technology refresh PTF is used to deliver a significant amount of new function between major releases. Beginning in IBM i 7.1, technology refresh PTFs replace modification releases.

For Licensed Internal Code, a technology refresh PTF contains new hardware-related function. The Technology Refresh PTF group contains the latest technology refresh PTF and additional PTFs. These PTFs provide the new functions contained in the latest technology refresh for the current release. To install a technology refresh PTF, you should order the Technology Refresh PTF group.

Prerequisite fix

A prerequisite fix is a fix that must be installed on your system before or at the same time as the fix that you want to install.

The system will prevent you from installing your fixes if you do not have the prerequisite fixes. Your fix cover letter or PSP information can identify other fixes that must be installed before or at the same time as the fix that you want to install.

Corequisite fix

A corequisite fix must be installed at the same time as the fix that you are requesting to install.

Your fix cover letter or PSP information can identify other fixes that must be installed before or at the same time as the fix that you want to install. In addition, system error messages can notify you that the fix that you are attempting to install has requisite fixes. The system checks that the corequisite fixes are installed at the same time. In this case, you need to verify that your fixes installed successfully.

Technology refresh requisite fix

A technology refresh requisite fix is a fix that must be permanently applied on your system before the fix you are installing is loaded.

The system prevents you from loading your fix if you do not have the technology refresh requisite fix permanently applied. Your fix cover letter or PSP information can identify other fixes that must be installed before or at the same time as the fix that you want to install.

Distribution requisite fix

A distribution requisite fix is required only for distribution purposes. The system does not require you to apply distribution requisite fixes, but it is recommended that they be applied with the dependent PTF. If you are sending a fix using IBM Navigator for i and Management Central, distribution requisite fixes are not sent.

Delayed and immediate fixes

Some PTFs (fixes) can be applied without requiring an IPL and other fixes can be applied only during an IPL. The cover letter tells you if the PTF is immediate or delayed.

Delayed fixes: Delayed fixes can be applied only during an IPL. Delayed fixes that affect the Licensed Internal Code can be applied immediately when the system is running on the A storage area.
Immediate fixes: Immediate fixes can be applied without requiring an IPL if the objects that they affect are not in use and if all requisite fixes can be applied immediately. Immediate fixes can also be applied when you do the next IPL. Use the Display PTF Apply Information (DSPPTFAPYI) command to determine if the selected PTFs can be applied immediately based on the state of all requisite PTFs.