1. See You at SHARE!
2. WLM I/O Priority
3. Update to January 2001 CPU Chart
4. Cheryl Watson’s TUNING Letter 2001, No. 3

1. See You at SHARE!

Next week is SHARE in Minneapolis. I’ll be giving my “Hot Flashes” on Friday morning at 9:30am (session 2543). Hope to see you sometime during the week. Please say hello. I tend to go to most of the sessions sponsored by the EWCP project (Enterprise Wide Capacity and Planning), because of their focus on performance. If you haven’t considered joining the project, please do, because then you can attend the closed sessions, which are extremely valuable. Our first closed session is Sunday at 3:00pm (2501) and our opening session is Monday at 1:30pm (session 2500). Please stop by.

2. WLM I/O Priority

WLM in goal mode calculates velocities either with or without I/O samples, depending on whether you’ve activated I/O Priority Management. I’ve often complained that, under I/O Priority Management, I/O disconnect time is viewed by WLM as positive, not a delay, when velocity is calculated. Because disconnect time is, in reality, a delay, the WLM calculation often produced both erratic and irrational velocities for goal mode management. I have recommended that people turn off I/O Priority Management because of this failing. Finally, IBM has changed the calculation to ignore disconnect time. You can apply an APAR, OW47667(New Function, 7/13/01), in OS/390 R8 or higher to remove I/O disconnect time from consideration in the velocities. Be careful, because if you are already currently using I/O Management and apply this APAR, all of your velocities will change.

After applying this APAR, you can go ahead and turn on I/O Management, although you will still need to determine the change in velocities and change goals appropriately after turning it on.

3. Update to January 2001 CPU Chart

Four of the workload MIPS for the 9672-Z67 were accidentally shifted in the January 2001 CPU Chart. The correct values should be:  IMS=990, CB84=955, CBW2=1173, and FPC1=1013. We’ll be sending out an updated spreadsheet to all online subscribers soon, and the next newsletter will contain an update sheet for the printed version. BoxScore customers received a note about this last week.

4. Cheryl Watson’s TUNING Letter 2001, No. 3

Although I had planned to complete issue #3 of the Tuning Letter before I left for SHARE, I don’t think I’ll get it done. My back didn’t fare well after our last move (our fourth in four years and hopefully the last for a VERY long time!), and I wasn’t able to write well. I’m feeling better, but I doubt that I’ll have this one finished until August 2. It will contain the details from my SHARE “Hot Flashes” session in case you have to miss it. Issue No. 4 is planned for the end of August and will contain my SHARE trip report. Thanks for your patience.

Stay tuned!