DFSORT is Needed

1
DFSORT is Needed

• At KBC SYNCSORT is used a primary sort package .
• DFSORT is needed for V8 Utilitities !
• DFSORT and SYNCSORT on the same system !
• Controlled by the linklist
• First libraries from SYNCSORT (primary Sort
  Package)
• Then libraries from DFSORT (secondary Sort
  Package) order
• SYS1.SICELINK
• SYS1.SORTLPA

DSNU000I DSNUGUTC - OUTPUT START FOR UTILITY,
UTILID REORG2 DSNU1044I DSNUGTIS
- PROCESSING SYSIN AS EBCDIC
DSNU1640I DSNUGUTC - Z/OS DFSORT LOAD
MODULE NOT LOADED. DSNU012I
DSNUGBAC - UTILITY EXECUTION TERMINATED, HIGHEST
RETURN CODE8
2
DFSORT Customization issues

• Most defaults are correct, we changed
• DYNAUTO IGNWKDD
• Unallocate existing sort workfiles, reallocate
  dynamically
• DFSORT critical messages send to a MSGDDN
• NOMSGDD (Critical) vs quit
• MSGCON (Critical) vs quit
• DYNALOC (SYSDA,10)
• DSA 128
• TMAXLIM 4194304
• There are lot of APARs talking about DB2
  DFSORT utility performance -setup
• Be aware that DFSORT can read ORTPARM and use
  some SYNCSORT parameters ! (is shown in dfsort
  messages)
• DFSORT usage DFSPARM DD as override dataset

3
Is it totally transparant ?

• We found out that it is NOT !
• Space allocation (pri,sec) method's differ !
• SYNCSORT
• bytes to sort / req workfiles
• Private algoritme work with extents, max 500
  Cyl Primary
• Does allocate workfiles only when NEEDED
• DFSORT
• bytes to sort / req workfiles
• Always allocates workfiles, even when not needed

SORT FIELDS(00006.0,00000.4,A,00012.0,00063.0,A,
00001.0,00005.0,A),FOR
MATBI,FILSZE000000183735816,DYNALLOC(SYSDA,03)
RECORD TYPEF,LENGTH(0074,0074,00
74)
OPTION MSGPRTALL,MSGDDNUTPRINT,MAINSIZE26864K
ICE201I 0 RECORD TYPE IS F -
DATA STARTS IN POSITION 1
ICE083A D RESOURCES WERE UNAVAILABLE FOR
DYNAMIC ALLOCATION OF WORK DATA SETS (064K)
74183735816/3 gt 4.2 GB per primary allocatie
4
Is it totally transparant ?

• How did we solve this
• Changed DFSORT default
• DYNALOC (SYSDA,4 -gt 10)
• Losed efficiency, less // taskes !
• Dynamically adjust SORTNUM when generating REORG
  jobs
• A lot of Batch Jobs used standard values for
• SORTNUM 4 SORTDEVT SYSDA
• SORTKEYS 1000000
• Mass Update all these jobs to get rid of these
  parameters
• Defined a SMS multitiered stogroup (find temp
  space in a other storage group)

IF(PGSIZE,GT,4) SORTDEVT SYSDA
SORTNUM 100 ELSEIF(ROHIUSED,GT,250000)
IF(ROHIUSED,LT,500000) SORTDEVT SYSDA
SORTNUM 50 ELSE
SORTDEVT SYSDA SORTNUM 100 ENDIF
ENDIF
5
Nice to known's

• If you use software packages that intercept
  dataset allocations (SMS, Pre Allocation
  Manager)..make sure that they do NOT change
  DFSORT allocations.
• If not 0C1 0C4 abends
• REORG utility
• SORTDATA is default and can not be changed !
• Which cost an EXTRA data sort more DASD
• After PK18059 SORTDATA YES/NO is optional
• We did not researched SMF16 to tune (DFSORT) sort