z/VSE IPL delayed because of larger memory
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Newer processors get more and more processor memory (real storage or processor storage). That is your virtual storage may fit into memory. You can use the NOPDS option in the IPL Supervisor parameter command and get rid of the definition for the page dataset. So you can avoid paging or, if running in a z/VM guest, let z/VM do the memory management.
The larger the memory in the LPAR or z/VM guest is the more CPU time is required during IPL to validate and clear all available page frames. This is especially visible for LPARs with low capacity settings (e.g. the A01 models) or low capping values (weights).
To avoid IPL delays because of larger memory, only define the memory to the LPAR or z/VM guest (DEFINE STORAGE) as required by the z/VSE system = the maximum virtual storage size that is required to run the z/VSE workload.
The maximum supported memory (real storage) in z/VSE is 32 GB. z/VSE supports up to 90 GB virtual storage.