by Robert Sample » Fri Aug 11, 2017 2:12 pm
There are 3 areas of memory on z/OS these days; below the line, below the bar, and above the bar. Below the line refers to memory addresses 0 to 16777215 (16 MB - 1) and is what is available when using 24-bit addressing (the original addressing scheme). Below the bar refers to memory address 0 to 2,147,483,647 (2 GB - 1) and is what is available when using 31-bit addressing (what IBM made available when programs starting running short of memory when using 24-bit addressing). Above the bar refers to memory address 4,294,967,294 (4 GB) and above and is what is available when using 64-bit addressing (what IBM made available to z/OS after programs started running short of memory when using 31-bit addressing). Unlike the first two, 64-bit memory does not allow programs to execute in it; only data may be stored there. And unlike the first two, 64-bit memory is only available on system z hardware and software.
Why is this important? Because if your SAS program needs more 31-bit memory than the 2 GB available, there is no physical way to provide that. MEMLIMIT refers to 64-bit memory and depending on what SAS needs the extra memory for, it may -- or may not -- help you.
Contact your site support group and work with them on your issue.