1. z/OS Correction
2. Cheryl Watson’s TUNING Letter 2001, No. 3
1. z/OS Correction
Thanks to Kent Ramsay of webMethods, Inc. for pointing out two typos in this issue of the TUNING Letter. (Note – these corrections were made to the print copy, but did not make it into the email copy.) On page 3, “Elsewhere in the Issue”, the last release for compat mode is z/OS 1.2, not OS/390 1.2. On page 17, (third bullet) the reference to OS/390 V1R3 should be z/OS V1R3.
2. Cheryl Watson’s TUNING Letter 2001, No. 3 Summary
The forty-four page 2001, No. 3 TUNING Letter was emailed to electronic subscribers on Tuesday, August 14. Print subscribers can expect to receive their issue by the end of the August. Here are a few of the topics we covered, taken from our “Management Issues”. You can purchase a printed copy of the current TUNING Letter for $85.
A large portion of this issue is about APARs (reported problems) and their fixes. For example, there was an APAR that reported problems (e.g. a system crash) if you went for over 51 days without an IPL after installing OS/390 R10. This happened to one site, IBM issued a correction, but because other installations didn’t check the current APARs (and this was listed as HIPER, of course), then several other installations ran into the same problem. Most of these problems occur because installations do not stay current on their maintenance level. If your installation doesn’t keep current, then this issue should prove invaluable for identifying potential problems before they occur. Have someone take the time to review the APARs I’ve included to see which ones might cause you problems in the near future.
Intelligent Resource Director (IRD)
z/OS running on a z900 can balance the system resources, such as CPU and channels, far better than your staff can manually. But it needs some preparation and a commitment to allow this dynamic management to occur. Our Focus article on page 26 by Al Sherkow describes the features of IRD, how they work, and what you need to do to use them.
CPU Per I/O
Several sites use some form of ‘after-the-fact’ benchmarks to determine whether they received the capacity they thought they were going to get after a hardware upgrade. We’ve previously talked about our software product, BoxScore, which uses that technique. Some of our BoxScore customers have installed new z900 processors and their findings with BoxScore are interesting, to say the least. Following our discussion of the findings are my recommendations for anyone who uses the CPU per I/O technique in analysis. (Page 8) Ed. Note – Tom wants me to point out that our introductory site license price of $4800 for BoxScore will be soon revert to our regular price of $9800.
Elsewhere in this Issue
IBM has stated that z/OS 1.4 will not require a new architectural level set. That means that your 9672 G5/G6 machines are good for a few more years (page 14). Also, the last release for compat mode is z/OS 1.2, which is due out this September. That doesn’t leave long for you to migrate to goal mode. You should be moving there today. It’s much easier than most people think, and it provides some significant improvements (page 17). Installations are always trying to determine how much overhead (or savings) migration to a new operating system or subsystem release will incur. IBM now has a free tool to help you make that determination (page 6). A new PDSE Monitor can cause several problems, but you can avoid them (page 5). A great downloadable (and free) book is available that describes the basics of UNIX, OS/400, MVS, VMS, and VM/CMS (page 7).