1. About Cheryl Watson’s Tuning Letter 2008 No. 5
2. Great Website for z/OS 1.10 Migration
3. IBM Red Alert
4. Putting z/VM to Sleep
5. Clarification to Tuning Letter 2008 No. 3
1. About Cheryl Watson’s Tuning Letter 2008 No. 5
The forty-six page 2008 No. 5 Tuning Letter was emailed to subscribers on December 5th. You may visit our Web site at http://www.watsonwalker.com to obtain subscription information. The following is a summary of just some of the contents of this latest Tuning Letter:
z/OS 1.10
The Focus article in this issue was on the latest IBM z/OS release, z/OS 1.10. This release became available in September 2008, and I realize that most installations will wait a while before migrating to it. The majority of installations take between six and 18 months to install a new release, and many sites simply move two releases at a time (skipping the odd or even release). But at least a third of the announced facilities for z/OS 1.10 are being made available to users who are running z/OS 1.7, 1.8, or 1.9 (i.e. almost everybody). z/OS 1.10 provides lots of new enhancements, and you can start taking advantage of many of them now. For example, JES2 dynamic exits should be implemented by every installation, and APARs make them available to all releases starting at z/OS 1.7. Many of the newest enhancements are to hardware features, such as the z10 server, the new cryptographic hardware, faster links, and more exploitation of zIIP and zAAP processors. Migration to many of these new facilities will not only improve your ROI, but will ease the migration to z/OS 1.10 (or 1.11) in the future. I’ve organized the enhancements by the release they may be applied to and component within the release. If, for example, you’re now running z/OS 1.8, you can review the changes available in z/OS 1.7 and 1.8 to determine which can be implemented immediately.
If you do choose to install z/OS 1.10 now, our 8-page summary of z/OS 1.10 enhancements should convince you that it’s certainly worth your time and effort. As usual, these enhancements include new facilities to simplify z/OS, improvements in usability (e.g. more ISPF features), and improvements in performance.
SMF
A large portion of this newsletter is devoted to SMF (System Management Facilities) processing. Because SMF is the main collector of data that you use for data center reporting, chargeback, performance management, capacity planning, and problem resolution, it’s extremely important to understand and manage the SMF records. Our z/OS 101 tutorial provides an introduction to SMF exits and describes the life of an address space (describing when SMF records are written and SMF exits are called). But the main article (SMF Update – Part 3) provides an analysis of SMF record sizes and volumes relating to address space information, and provides recommendations on how (or whether) to collect and use the records.
Elsewhere in This Issue
In our User Experiences section, we describe a CICS problem with high CPU and a GRS contention problem. In our News section, we provide the latest APARs of interest, new publications, and some excellent links to useful documents or presentations. Of special importance are the New Function APARs that are often not included in routine maintenance, but can provide new features or improved performance. In IBM Announcements, we describe a new facility called High Performance FICON for System z (zHPF) on DS8000s.
2. Great Web site about z/OS 1.10 Migration
In our last Tuning Letter, we discussed the migration to z/OS 1.10 and included a 3-part SHARE presentation by Marna Walle in our references. But in the latest minutes of the SHARE zNextGen teleconference minutes I found an even better reference. Brian Peterson pointed out this link from the IBM Education Assistant. It contains not only Marna’s presentation, but provides her actual speech.
3. IBM Red Alert
IBM issues Red Alerts for especially important APARs. You may subscribe to their service at http://www14.software.ibm.com/webapp/set2/sas/f/redAlerts/home.html.
The following Red Alert (2008.12.16) was just released:
Abstract: Partial Release of VSM Extended Format Data sets on z/OS 1.10 using OEM Security Product, may cause loss of access to data sets due to an error in DADSM Partial Release processing.
Description: In z/OS 1.10, when attempting to release space on VSAM extended format data sets, an ABENDC04 may occur in IGG020P1 or IGG020P2. On the subsequent Open, you may receive a message IEC331I, which indicates loss of access to the data set. If this occurs, please open a PMR with IBM and we can help regain access to the data set. APAR OA27386 (OPEN) has been created to resolve this issue. See the APAR text for additional details.
4. Putting z/VM to Sleep
We just ran into an interesting situation while doing development on ourGoalTender product. You can be successfully collecting SMF data in z/OS, and then put the controlling z/VM to sleep. (This function is normally only used on development systems.) When you start up z/VM again, RMF no longer collects records because of an incorrect timestamp in SMF. An IPL of z/OS corrects the problem. We don’t know if an APAR will be issued, or whether the problem occurs in more applications than RMF. If you’ve run into this, please let us know.
5. Clarification to Tuning Letter 2008 No. 3
While discussing SMF parameter in our Tuning Letter 2008 No. 3 on page 18, I said the following:
The EXCP sections are always present in batch jobs and TSO records, but are only located in records for started tasks if DETAIL is specified for SYS or SUBSYS(STC). The default is NODETAIL.
But this should have been expanded to read:
The EXCP sections are always present in batch jobs and TSO records for record types 30, subtypes 2, 3, 4, and 5. For started tasks, the EXCP sections are always present in record type 30, subtypes 2 and 3. If you specify DETAIL for SYS or SUBSYS(STC), the EXCP sections are also present for started tasks in the type 30, subtypes 4 and 5. NODETAIL is the default.
Best wishes for a wonderful holiday!