1. Highlights of Cheryl Watson’s TUNING Letter 2007 No. 1
2. Time Change Reminder
3. Important Media Manager Fix
4. 2006 TUNING Letter DVD Available
5. SHARE Proceedings for Tampa
1. Highlights of Cheryl Watson’s TUNING Letter 2007 No. 1
The forty-five page 2007 No. 1 TUNING Letter was emailed to subscribers on March 6, 2007. Single issues may be obtained for $155 each from our Web site at http://www.watsonwalker.com. The following is a summary of just some of the contents of this latest TUNING Letter:
SHARE in Tampa
Since our last issue, we attended the winter SHARE conference in Tampa, Florida and came home with all kinds of exciting information. Although more information will appear in future issues, there were some critical items that we just had to include here. Please read our SHARE Highlights article on page 13 for more details. You will find details about some recommended fixes that can improve your system performance and help you avoid costly outages. These were passed along by IBM speakers in several of the sessions. On the final day of SHARE, Cheryl also presented the seventeenth edition of her popular Hot Flashes session where we pass along important hints and recommendations. Although we will explore this in more detail in a future issue, you can download a copy of the presentation today from our Web site (select Articles, then Presentations).
Final DST Reminder
We have mentioned this in previous issues, but we wanted to give you one final reminder. According to IBM, there are still some customers who are not aware that a new law takes effect this year, and Daylight Saving Time will start earlier than usual (March 11, 2007) for many customers. Read page 17 to find out more, including some new information we heard at SHARE.
zNALC Pricing Option
IBM has announced a new pricing option that may allow certain customers to pay less for z/OS. As part of that announcement, it was also stated that z/OS.e 1.8 will be the last release of that operating system. You can read all about this new zNALC (System z New Application License Charge) pricing option on page 39. The intent of z/OS.e was to provide a stripped-down version of z/OS at a lower price for customers who were running certain types of ‘new’ workloads (such as Java). This is the same goal of zNALC, which is why z/OS.e is being discontinued. The older NALC pricing metric will also be replaced by zNALC.
Migration Assistance
Because IBM is releasing a new z/OS release each year, it is a good bet that many organizations invest a lot of time and money planning their migrations to these new releases. IBM also dedicates a lot of their resources to make sure your migration efforts are successful. Read page 19 to learn about a new automated tool that may help. You will also like the price, because it’s free.
Elsewhere in this Issue
See page 38 for information about a new IBM Red Alert describing a catalog problem that may affect an entire sysplex. • If you are running DB2 on one of the new System z processors, then you will want to read about a MIDAW performance issue on page 28. Although MIDAW offers improved I/O performance, taking our recommendations may make it even better. • Speaking of DB2, if you use the ULC (Usage License Charge) billing option then a recent IBM change may cause you to see an unexpected change in your bill. You can read more about this on page 30.
2. Time Change Reminder
We wanted to include one final reminder for our North American readers about the Daylight Saving Time change that will occur this coming Sunday, March 11, 2007. This would normally not be news, except for the fact that the Energy Policy Act of 2005 causes Daylight Saving Time to be extended by four weeks starting this year. This means that the time adjustment will occur three weeks earlier than usual, and has the potential for causing problems for any hardware, software, or device that performs Daylight Saving Time adjustments.
The revised rules will be observed by the United States, Canada and Bermuda, so you may be affected if you have computing operations in any of these areas.
For our TUNING Letter subscribers, we have mentioned this in our most recent issue (see TUNING Letter 2007 No. 1, page 17), and in previous issues (TUNING Letter 2006 No. 3, page 10 and TUNING Letter 2006 No. 6, pages 35-36).
If you are not a TUNING Letter subscriber, you may obtain information about what IBM is doing using the link http://www.ibm.com/support/alerts/us. Similar information should be available from other hardware and software vendors.
3. Important Media Manager Fix
One of our readers recently alerted us to a very serious problem in the Media Manager component of z/OS. It was too late to include this information in our latest TUNING Letter, but we thought we would include it here. According to our reader, the problem was caused by APAROA10379, which added support for the new MIDAW function that improves I/O performance on the System z9 processors. The problem is that the APAR also opens a small timing window that can expose you to Media Manager errors on rare occasions. For our reader’s organization, the problem became worse after they applied OA18401, which seemed to open the timing window wider and lead to more frequent problems.
Based on some discussions with IBM, a new APAR has been created to correct the problem. If you look at the original APAR OA10379, it has now been marked in error, with a reference to this new HIPER APAR:
- OA20028 (DFSMS for z/OS 1.6+, 2Mar2007) – ABEND0C4 in ICYSTOR + Many Other ABENDs in IOS and Media Manager and in DB2. 07/03/02 PTF PECHANGE. When the Media Manager expands the structures that manage its pooled SQA storage, a new control block is chained incorrectly resulting in the overlaying of a pointer to an existing storage block. This can result in the potential loss of serialization to the storage blocks and can lead to concurrent use of the same storage by multiple requests. In addition to the symptoms listed above, this may also cause an ABEND SB78 in module IGVVSTOR and an ABEND S066 in module IEAVEDS0.
Here is the list of those fixes now marked in error: UA31776, UA31775, UA30803, UA29067, UA30802, UA22376, UA30804, UA20611, UA22372, UA31774, UA25366, and UA21586. If you have applied any of these, then you should investigate OA20028.
Thanks to our reader for alerting us to this critical APAR.
4. 2006 TUNING Letter DVD Available
We are pleased to announce that the 2006 version of our TUNING Letter DVD was mailed to all subscribers on January 25, 2007. None of these were returned as undeliverable, so if you are a TUNING Letter reader, then someone in your organization should have received it. If you think you somehow got overlooked, please email admin (at) watsonwalker.com and we will investigate.
The DVD contains all of the TUNING Letter issues from 1991 through 2006, as well as several versions of our useful CPU Chart. We offer the CPU Chart for sale as a separate item, but TUNING Letter readers get it for no additional charge. You will also find many presentations that we have given at user groups (such as SHARE and CMG), along with articles that have been printed in technical journals. The index makes it easy to find what you need, and there is also a search function that will search the entire volume for a specific keyword or argument.
This year we switched from a CD-ROM to a DVD, because of the volume of material. If you are currently not a TUNING Letter subscriber, you should consider subscribing just for this one valuable resource. It truly is an encyclopedia of performance and capacity planning knowledge in a very small package.
5. SHARE Proceedings for Tampa
Most of the session proceedings from the most recent SHARE conference in Tampa, Florida can now be downloaded from the SHARE Web site (http://www.share.org). There is currently no special authorization needed to access these, so even those organizations that do not belong to SHARE can benefit from this valuable resource. Over 700 different sessions were presented in Tampa, on a wide variety of topics.
Once you are in the proceedings area of the Web site, you can search by session number, subject track, project, program, or speaker name. You can also search by keyword. For example, searching for the keyword ‘zIIP’ resulted in eight different sessions that included information about this new specialty processor.
Stay tuned!