System paging performance comes from the SMF75 record. This record is supported and part of zOSMON reporting. The ZOSPAGE report provides this information. It is likely users will want to set up operational alerts based on paging rates to ensure installations are aware of spikes in page rates. The following ZOSPAGE report shows one such spike.
Report: ZOSPAGE Z/OS PAGE Detail Report Velocity Software Corporate Monitor initialized: 10/01/20 at 11:52:00 on Z15S --------------------------------------------------------------------------- Time/ Volume Devc Page <-----Page Slots------------> ASMSYSID Serial Nmbr Type Total MaxU MinU Avg Bad Used page I/O ------ ------ ---- ----- ----- ----- ----- ----- ----- ----- ----- ----- 11:59:00 - 12:00:00 V24A Totals: 1025K 418K 418K 418K 0 1 7.9 3.5 24ASPG 0246 PLPA 234K 16366 16366 16366 0 0 0 0 24ACAT 0241 Commn 9719 5567 5567 5567 0 0 0.0 0.0 24ASPG 0246 Local 781K 396K 396K 396K 0 1 7.8 3.5 --------------------------------------------------------------------------- 12:00:00 - 12:01:01 V24A Totals: 1025K 425K 418K 423K 0 5 158.9 9.3 24ASPG 0246 PLPA 234K 16366 16366 16366 0 0 0.4 0.4 24ACAT 0241 Commn 9719 5608 5568 5602 0 0 0.9 0.4 24ASPG 0246 Local 781K 403K 396K 401K 0 5 157.6 8.5
The question then is what caused this spike - can it be related to a specific job, and if that is CICS, can it be related to a specific transaction or increase in load.
In looking at first the ZOSJCPU (Job CPU) report, specifically at the storage component, and then focusing on "totals". One can see additional storage requirements occur in this relatively static environment consistent with the spike in page rates seen above.
Report: ZOSJCPU z/OS Jo1.1 10/09/20 Page 46 Monitor initialized: 10/01/2 ---------------------------------------------------- SYSID <------JOB----------> >zip Name JobID Step Real Max Priv Shrd on Nbr p Used Aux Stor Stor CP ---- -------- -------- --- - =--- --- ---- ---- --- 11:52:00 - 11:53:00 V24A Totals . 0 827 787 41K 1088 2.0 Totals . 0 849 805 185K 1088 1.0 Totals . 0 850 805 184K 1088 2.0 Totals . 0 850 805 184K 1088 0 Totals . 0 849 805 185K 1088 2.0 Totals . 0 849 806 184K 1088 1.0 Totals . 0 849 806 184K 1088 1.0 11:59:00 - 12:00:00 Totals . 0 849 806 185K 1088 2.0 12:00:00 - 12:01:01 Totals . 0 873 811 184K 1088 3.0 Totals . 0 849 811 184K 1088 2.0 Totals . 0 849 811 184K 1088 1.0
At the time of interest, there was an increase in page space used, as well as real storage requirements. The next question is which job(s) changed from one minute to the next.
Comparing jobs from one interval to the next allows us to determine what caused the spike. Eliminating all of the small jobs using less storage than 10MB, showing just the relevant jobs showed the following:
Report: ZOSJCPU z/OS Jo1.1 10/09/20 Page 46 Monitor initialized: 10/01/2 ---------------------------------------------------- SYSID <------JOB----------> >zip Name JobID Step Real Max Priv Shrd on Nbr p Used Aux Stor Stor CP ---- -------- -------- --- - =--- --- ---- ---- --- 11:58:00 - 11:59:00 V24A Totals . 0 849 806 184K 1088 1.0 C24ASTND STC02421 1 0 36.5 12 2230 0 0 IZUSVR1 STC00788 3 0 259 168 21K 64.0 1.0 MQA1MSTR STC00805 1 0 46.9 46 316 0 0 MQA2MSTR STC00806 1 0 47.0 44 412 0 0 OMVS OMVS 1 0 34.3 14 7200 0 0 SMSPDSE System 1 0 11.9 14 55.0 0 0 ZFS STC00756 1 0 385 490 593 0 0 ---------------------------------------------------- 11:59:00 - 12:00:00 V24A Totals . 0 849 806 185K 1088 2.0 C24ASTND STC02421 1 0 36.5 12 2230 0 0 IZUSVR1 STC00788 3 0 259 168 22K 64.0 2.0 MQA1MSTR STC00805 1 0 46.9 46 316 0 0 MQA2MSTR STC00806 1 0 47.0 44 412 0 0 OMVS OMVS 1 0 34.3 14 7200 0 0 SMSPDSE System 1 0 11.9 14 55.0 0 0 ZFS STC00756 1 0 385 490 593 0 0 ---------------------------------------------------- 12:00:00 - 12:01:01 V24A Totals . 0 873 811 184K 1088 3.0 C24ASTND STC02421 1 0 36.5 12 2230 0 0 IZUSVR1 STC00788 3 0 259 171 21K 64.0 2.0 JVMJCL86 JOB02708 1 0 23.2 0 12.0 0 1.0 <-------- MQA1MSTR STC00805 1 0 46.9 46 316 0 0 MQA2MSTR STC00806 1 0 47.0 45 412 0 0 OMVS OMVS 1 0 34.3 14 7200 0 0 SMSPDSE System 1 0 11.9 14 55.0 0 0 ZFS STC00756 1 0 385 491 593 0 0
And at this point, we can see one job that on this system runs every 30 minutes and causes a spike.
The point of this analsys is to show how to identify spikes in storage utilization and paging.
