Since there is no default OMVS segment under z/OS 2.1 and above, what OMVS segment will be associated with the Top Secret address space?
In z/OS 2.1 and above, since there is no default OMVS segment, Top Secret will recognize that the Top Secret address space does not have any USS information and will automatically provide one for Top Secret. Therefore, no changes are required for the way the Top Secret address space is started when upgrading to z/OS 2.1 or above.