Tip of the week is on summer holiday. The next tip will be published on the 10th of august 2009.

Ugens tip holder sommerferie. Næste tip udkommer den 10. august 2009.

Most of us who are working with mainframes has experienced and will continue to experience that our mainframe tasks are carried out with a speed that we do not find satisfactory. It is typically between 10am and 3pm. During this time slot the MVS systems are heavily loaded because most of us work between 10am and 3pm. This is of course understandable, but what if your task is being carried out in a very slow fashion outside this time slot. How do you then find out whether your MVS system is under stress or not.

The fastest and easiest way is to enter SDSF or SYSVIEW. In SDSF you must carry out the command DA for Display Active and in SYSVIEW you must use the command ACT or ACTIVITY. Many installations using SYSVIEW has configured DA as a synonym for ACT. If you are using SDSF please look at the upper left corner of the panel. Here you find two % figures. If these two figures are high (above 80) then your MVS system is under stress. If one of the figures is high and the other is more than 10% lower then your MVS system is very stresses and it is competing with other higher prioritised MVS systems for the CPU's.

In SYSVIEW you will most likely not find any % figures anywhere on the System Activity panel. You can make them visible by carrying out command PROFILE on the System Activity panel. On the displayed panel (Profile for <userid>) you type in an S besides Miscellaneous Section and press Enter. A new panel is displayed with a lot of different fields. Look for the field Overview Display which is located below the heading Overview Display Options. Fill in the field with the value YES and the field Overview Format with the value LONG and press Enter. Go back using F3 until you are at the System Activity panel again. Hopefully it now looks a bit like this:

SYSVIEW 11.0 MVSX ------------- System Activity ------------- 24/05/06 08:24:51
Command ====>                                                 Scroll *===> CSR
------------------------------------------------ Lvl 1 Row 1-12/12 Col 1-79/430
(r)   Pct% ..25..50..75.100  -Condition-  ---Ready---  ---Paging---  --Common--
CPU    55%                     ENQ NoSMF  ASIDs     1  Slots    14%  ECSA   28%
LCPU   51%                     RES NoWTO  Tasks     1  Rate       6  ESQA   77%
                             NoDMP   TAP  ----I/O----  AFQA    608k   SQA   33%
Spool  55%                                Rate   5536  UICA    2540   CSA   41%
-------------------------------------------------------------------------------
    *                          ALL            ALL
Cmd Jobname  Stepname Procstep Type  Jobnr Jc Status CPU-Time Limit Clocktime
    MYJOB001 MYSTEP01          STC     321 å  NS        0.336 86400  00:53:03

The two fields CPU and LCPU corresponds to the two fields in the upper left corner of the DA panel in SDSF and is interpreted in the same way. You can also find other interesting information on the above panel. Below the heading ---Ready--- the fields ASIDs and Tasks shows you the number of Address spaces and TCBs ready to perform tasks on a CPU. If these two figures begins to increase or are high then your MVS system is in deep trouble.

If you consult the different figures described above and concludes that your MVS system is not under stress you have to look for other reasons why your task or tasks are performing badly. If you have questions regarding other fields on the panel above please send me a mail.