1. SHARE Conference
2. Important APARs
3. Cheryl Watson’s TUNING Letter 2000, No. 3 Update
1. SHARE Conference
We’re about to leave for the SHARE conference in Boston (July 23-28). I’ll be giving one session on Friday morning at 9:30am: Session 2543 – Cheryl’s Hot Flashes IV. It’s a collection of some of the latest tips I’ve found, along with some old goodies that are still important. I hope to see you there. For more information, see http://www.share.org.
2. Important APARs
While we were in China, several readers dropped a note to me about some very important APARs. Since the next issue of the TUNING Letter won’t be until after SHARE, I thought you would be interested in these:
APAR OW44517 (Hiper) – After OW39132, IEAVEOR (IOC003) may not decrement ASCBTCBS (closed 00/07/17, and applicable to OS/390 R5 – R9). The PTF doesn’t fully describe what’s happening here, although it does indicate that performance degradation (seen in MVS uncaptured time) could be as high as 10%. Bob Kemper of Alltel saw a 20% increase in their batch window after implementing R8 with high priority production jobs swapped out with reason “Unilateral” while low priority jobs were swapped in with high reported velocities. (Bob points out that there a number of REQs for the PTFs.) Steve Schwaller of KeyBank saw a decrease in unilateral swaps from 5000 to 150 during prime shift after applying the correcting PTFs. The impact of this problem seems more pronounced in goal mode. It’s apparent only after applying the PTF for APAR OW39132 in R5-R8, or after migrating to R9.
APAR OW43378 – Goal mode resource group minimum not being honored (open 00/07/11). There are situations where the resource minimum may not be met even when the service classes in the resource group are missing their goals.
APAR OW45117 – Higher importance server address space may be delayed by lower importance work (open 00/06/27). One more APAR relating to this condition with CICS or IMS transactions in goal mode being delayed by lower importance work on CPU constrained systems.
APAR OW42395 – Server address space swapped out and not swapping back in (closed 00/05/22, OS/390 R3 – R8).
APAR OW45192 – Invalid RCAECPU (CPU Service Units) for enclaves (open, applicable to OS/390 R6 – R8 when OW40548 applied). Negative or invalid (huge!) service units values may show up for performance groups or service classes that contain enclaves. One site running heavy DDF work was especially affected by this. Barry Merrill has a good description of it in his MXG Newsletter Thirty Seven at http://www.mxg.com.
3. Cheryl Watson’s TUNING Letter 2000 No. 3 Update
There were some small typos in the last TUNING Letter issue. Many thanks for the corrections! (Note – some of the corrections were made to the print copy, but did not make it into the email copy.)
WSC Flash10028 – “SMB Password Encryption Support” on page 5. The description referred to SMF instead of SMB. Thanks to David Alcock of American Electric Power.
SMF Type 42 Maintenance, page 9. “For APARs OW18678 and OW19055, the 11C0 and 11D0 columns have been erroneously shifted to the right.” These PTFs are applicable to 11B0 and 11C0 instead. Thanks to Scott Ruhe of Medical Mutual of Ohio.
Using FDR to COPY/MOVE HFS files, page 26. Stephen Mednick of Computer Supervisory Services pointed out that FDR users need to be running Version 5.3 level 40 or higher instead of Version 5.2.
The CF Levels article on page 18 mentions the use of system-managed rebuild for sysplexes running at R8 or later on CFCC Level 8. One reader cautions that to implement this you need to define a new set of CFRM Couple data sets formatted with the new option: ITEM NAME(SMREBLD) NUMBER(1) and switch to them. Otherwise your request for rebuild is rejected.