A while back, IBM provided SMF data-recording relief with "software compression" options for CICS and DB2 at the region/subsystem level -- that has worked quite well for very large IBM z/OS sites although at the expense of CPU-time consumed in the region/subsystem (for compressing certain SMF types/subtypes) and then again as needed for post-processing decompression of the SMF data as well.
And so recently, IBM introduced the zEDC feature/card compression technology, new with zEC12 / zBC12 and now with z13 z Systems technology solutions. What a marketing move on IBM's part, of course, but consider we are seeing up to 10-to-1 SMF data compression with zEDC and it is being done "outboard" (CPU processing in the zEDC CPU / card) and quite efficiently. And, beyond SMF, sequential dataset compression is also being exploited via DFSMS DATACLAS, to include DFHSM data management and other supported application/utility interfaces.
However for this discussion/post, the interest is about how can one double-check quickly to see that in fact CICS/DB2 SMF compression has been deactivated? Well, there flag-indicator fields present in the SMF data header area (oddly not always populated consistently, as is the case with DB2) -- nonetheless the information is available to double-check and if you have a suitable SMF post-processing utility, such as SAS and MXG from Merrill Consultants, you can quickly extract SMF data types involved, say for today, and complete a verification -- here's a sample CA SMF DIRECTOR EXTRACT and MXG/SAS data-analysis request:
//STEP1 EXEC xxxxxxxx <- your SMF DIRECTOR EXTRACT PROC
//* ** EXTRACT CICS/CMF SMF 110 SUBTYPE 1 FOR MXG ANALYSIS **/
//EXTRACT DD UNIT=TAPE,DISP=(NEW,PASS),BUFNO=20,DSN=&&SMFDEXTR
//SYSIN DD *
EXTRACT ALL SELECT(110.1) TODAY .
//STEP2 EXEC MXGSAS <- your MXG software PROC
//* ** DECODE SMF EXTRACT DATA AND GENERATE SASLIST MXG REPORT **/
//SMF DD DISP=(OLD,DELETE),BUFNO=20,DSN=&&SMFDEXTR
//SYSIN DD DATA,DLM=ZZ
Even though IBM has indicated that zEDC compression further increases SMF 101/110 size-reduction, it may be worthwhile to turn off the "software" compression option for DB2 and/or CICS and let the zEDC card/feature handle the chore.