System Recovery Boost on IBM z15

System Recovery Boost on the IBM z15 server expedites planned operating system shutdown, either planned or unplanned operating system initial program load (IPL), middleware and workload restart and recovery, and the client workload execution that follows, to accelerate service restoration around downtime. It does this by providing limited-duration “boost periods” that deliver significant usable additional processor capacity and parallelism. On subcapacity machine models, it provides a boost in processor speed by running the general-purpose processors at full-capacity speed, for the boosting LPARs only, and only during the boost periods. It makes all available processing capacity defined to the boosting images available to process any kind of work, “blurring” general-purpose processor and specialty processor capacity together during the boost period. System Recovery Boost also expedites and parallelizes processor reconfiguration actions that may be part of the client's overall restart and recovery process, as orchestrated by Geographically Dispersed Parallel Sysplex (GDPS) automation. Optionally, System Recovery Boost provides the ability to add additional processor capacity from the client's unused “dark cores” via activation of a new type of temporary capacity record. All of this can be accomplished without increasing the client's IBM software billing costs or the processor consumption associated with the client's workload during these boost periods.