STP is available starting with the z890/z990 family of servers, and is supported by z/OSe V1.7, and z/OS V1.7 and above.

Software support for Timing-only links

Timing-only links are Coupling links that allow two servers to be synchronized using STP messages, when a CF does not exist at either end of the Coupling link. You should consult the Preventive Service Planning (PSP) buckets for STP related maintenance. They are listed in the xxxxDEVICE PSP bucket where xxxx is the machine type.

Attention: IBM has removed the Enhanced PSP Tool host compare program, and associated extract files from the IBM Technical Support Web site.

SMP/E 3.5 (also part of z/OS V1.10) provides new function which can greatly simplify the identification, verification, acquisition, and installation tasks for service documented in PSP buckets by processing a new kind of HOLDDATA which associates PTFs to fix categories. Each ++HOLD statement identifies an APAR and its resolving PTF needed to provide support for the fix category. The new FIXCAT HOLDDATA is now being delivered with existing ERROR HOLDDATA. Fix categories have been defined for hardware devices, new software FMIDs, and selected hardware and software functions.

For example, for the z10 platform the following fix categories have been defined:

Additional fix categories may be added in the future.

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Operating Systems

IBM System z supports multiple operation systems:


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