You can obtain a general estimate of the total size of all paging data sets by considering the following space factors.

1. The space needed for the common areas of virtual storage (PLPA and extended PLPA, MLPA, and CSA).
2. The space needed for areas of virtual storage: private areas of concurrent address spaces, and concurrently existing VIO page data sets. (The system portion of concurrent address spaces needs to be calculated only once, because it represents the same system modules.)
3. If you add storage-class memory (SCM) to your system, the required sizes of your paging data sets for VIO and local page data sets must be large enough to accommodate VIO workload, plus additional space for paging spikes beyond what SCM can accommodate.