We're an all 7.3 shop.  I'll just go with your comments going along with 
others following this thread.
Our hosting lpar
System ASP . . . . . . :    23277 G
% system ASP used  . . :    70.9458
With the *ALWSAV set to *NO,
and our fast VTL
and the fact that our hosting lpar solely does hosting,
a full system save takes 6 minutes.  Not bad for 70% of a 23TB system. 
Then again, when almost all of it is ignored...
From PRTDSKINF:
Total disk space on system in 1,000,000 
  bytes  . . . . . . . . . . . . . . . . :   23277381
Main storage size in megabytes . . . . . :   31196 
                                                % of         Size in 
Description                                     Disk     1,000,000 byte
User libraries                                   .11           25397.20
User directories                               70.72        16461876.52
Folders and documents                            .00                .11
QSYS                                             .01            2272.86
Other IBM libraries                              .04            8764.04
Licensed Internal Code                           .03            7350.38
Temporary space                                  .06           12944.54
Unused space                                   29.03         6757345.94
System internal objects                          .00             224.48
Objects not in a library                         .00                .00
TOTAL                                         100.00        23276176.07
From PRTDIRINF, Page  8009:
 ________________________________________________________________
   Directory . . :   /QFPNWSSTG 
 
 Description 
 Total space used by this directory 
Number of        % of              Size in 
 Objects         Disk             Megabytes
       82         .00                   .64
 Total space used by objects in this directory and subdirectories
Number of        % of              Size in 
 Objects         Disk             Megabytes
      447       70.52           15655397.12
Rob Berendt
As an Amazon Associate we earn from qualifying purchases.