we've migrated from DB2 v9 CM to NFM on one test lpar.
Now our sorts "likes" hiperspace workfiles and reports high number of service units. Before that they choose rather other types of workfiles.
For example the same sort steps before and after migration:
My guess is that there is now more storage available on the system so DFSORT is exploiting it for Hiperspace sorting. If you want to restrict DFSORT so that it cannot use available central storage fo sorting, you can modify your installation default like EXPMAX from the shipped default of MAX to something more restrictive. If you want to disable it completely, set EXPMAX=0.
Thanks for the reply and tips, Dave.
I decided to use HIPRMAX=0 to disable Hipersorting.
An additional unpredictable HPT overhead distorted our batch tests results.
I concerned to miss an unknown APAR or PTF so my subject ...