1. Cheryl Watson’s Tuning Letter 2011 No. 6
2. Correction to Tuning Letter 2011 No. 6
3. RSM Problem?
4. HIPER APARs for DS8700/DS8800s
1. Cheryl Watson’s Tuning Letter 2011 No. 6
The 40-page 2011 No. 6 Tuning Letter was emailed to paid subscribers on December 29, 2011. You may visit our website at www.watsonwalker.com to obtain subscription information and the table of contents. The following is the Management Summary from that issue, talking about some of the contents of this latest Tuning Letter:
Service Level Management
Service levels are the level of service (in terms of response time and availability) that the data center provides to the users. Service level objectives (SLOs) are needed by every installation today, and service level agreements (SLAs) are needed in many, but not all, installations. Service levels are used for performance analysis, capacity planning, data center management, and management reporting. They often have an impact on chargeback. But managing service levels is not an easy task. This issue will start a series of articles on service level management.
As an example of the complexity of managing service levels, consider an installation which has guaranteed 95% z/OS availability during prime shift. That actually allows two hours of outage per week. And because that objective only covers z/OS, the applications could be down for three hours a week, and yet the service level is met. We discuss those issues and provide an description of the many types of service levels that might need to be present in your installation.
z/OS 1.13 Parmlib
Many of the z/OS 1.13 enhancements need to be implemented with parameters in members of Parmlib. Most new facilities are disabled when distributed in a new release because customers have indicated that they don’t want to see unintended changes in behavior during a release migration. That means that after a new release is installed, you need to go into parmlib and enable the facilities in order to take full advantage of the enhancements. In this issue, Cheryl takes each parameter that is new with z/OS 1.13 and describes which facilities to enable, and which to leave disabled.
User Experiences
Based on our reader survey, we know that one of the favorite sections in our Tuning Letter is the User Experiences section. In this issue we cover several DB2 experiences, tuning for DFSORT, an increase in CPU on a z114, programs to analyze CPU Measurement Facility sample data, and some hints and tips on other topics.
Elsewhere in This Issue
You’ll also find many other useful or interesting items throughout this newsletter: An important Facebook site for z/OS• Important publications and papers from IBM • SMFand Information APARs to help you identify useful maintenance.
2. Correction to Tuning Letter 2011 No. 6
On page 21, we reprinted an IBM-Main forum posting about how to get a list of linkedit dates for a load library. Unfortunately, the JCL was only for z/OS 1.10 and earlier. A few readers wrote in to suggest an alternative for z/OS 1.11 and later. So here is a repeat of the article with changes added for z/OS 1.11 and up:
I thought that this was a handy item that Art Celestini of Celestini Development Services provided on IBM-Main. A poster asked how to get a listing of all of the compile dates in a load library. Art provided a set of JCL to provide the link-edit dates of all modules in a library. That seems close enough to me. Thanks, Art. IBM-Main archives are at bama.ua.edu/archives/ibm-main.html, and Art’s response was on July 4, 2011 (z/OS Newbie question).
For lack of a better universal tool, I use the following to obtain the link-edit dates for all of the load modules in a library. Getting the compile dates of all of the component object modules would seem to be much harder because of the variety of compilers that might be involved.
//*-------------------------------------------------------------
//*
//* This job serves to list the link-edit dates for all members of
//* a PDS/PDSE load library. It works by running AMBLIST against
//* the entire library with its output going to a temporary data
//* set and then runs SORT to extract only the lines containing the
//* module name and date the module was linked.
//*
//* Change the SET SYSLIB below to the desired load module library.
//*
//*-------------------------------------------------------------
// SET SYSLIB=<target-load-library>
//*-------------------------------------------------------------
//LOADLIB EXEC PGM=AMBLIST
//*SYSPRINT DD SYSOUT=*
//SYSPRINT DD DISP=(NEW,PASS),DSN=&&AMBLIST,
// UNIT=(SYSDA,3),SPACE=(TRK,(3000,300),RLSE),
// DCB=(RECFM=FBA,LRECL=133,BLKSIZE=0)
//SYSLIB DD DISP=SHR,DSN=&SYSLIB
//SYSIN DD *
LISTIDR OUTPUT=ALL
//*-------------------------------------------------------------
//SELECT EXEC PGM=SORT
//SYSOUT DD SYSOUT=*
//SORTIN DD DISP=(OLD,DELETE),DSN=&&AMBLIST
//SORTOUT DD SYSOUT=*
//SYSIN DD *
INCLUDE COND=(6,6,CH,EQ,C'MEMBER',OR,11,9,CH,EQ,C'THIS LOAD')
OPTION COPY
//
This provides a short listing of one line per load module. If you want the dates of each CSECT with the load module, change the INCLUDE statement above to read:
INCLUDE COND=(6,6,CH,EQ,C'MEMBER',OR,11,9,CH,EQ,C'THIS LOAD', - OR,85,1,CH,EQ,C'/')
This provides a longer listing with one line for each module and one line for each CSECT within the load module. Try it both ways.
3. RSM Problem?
In our last Cheryl’s List #155, we mentioned an RSM problem where the number of Hiperspace frame counts in central continued to grow. One customer indicated that they had seen the same problem in z/OS 1.11, was given a couple of slip traps that were never triggered, so dropped it.
Scott Wigg and Doug Henry from USBank recently migrated to z/OS 1.12 from 1.11 and started encountering very high hiperspace paging. IBM opened APAR OA38295 for this situation, but noted that internally the count of Hiperspace pages in Real is larger than the TOTAL FRAME count. So this actually might be the same problem.
- OA38295 (z/OS 1.12-1.13, OPEN 8Dec2011) – High Paging of Hiperspace Pages. Hiperspace pages may be paged to AUX instead of staying in REAL storage on an SWRITE.
4. HIPER APARs for DS8700/DS8800s
We’re looking for user experiences with any of the following features. If you’ve tried the following and had good or bad experiences, please let us share those experiences with our readers. Steve Mawhinney, from a large financial institution, told us about HIPER APAR OA38260 for zHPF (zEnterprise High Performance FICON) regarding data loss on DS8700/DS8800s running microcode 6.2, after the application of PTFs for OA34661.
- OA34661 (DFSMS 1.11-1.13, 10Nov2011) – New Function. This provides Media Manager support for scattered reads and write, bidirectional data, and format writes in zHPF channel programs. Note – This is not marked as in error.
- OA38260 / OA38263 / OA38264 (z/OS & DFSMS 1.11-1.13, 8Dec2008) – Potential DS8700/DS8800 Loss of Access and Job Abends. (The phrase “…a DS8700/DS8800 host adapter panic will occur…” struck me as funny.) OA38264 was opened 12/2/2011 and will need a userid to access the link. A local fix is to disable zHPF if you’ve applied OA34661 and have applied the 6.2 microcode.
Stay Tuned!