David, For BSAM and QSAM looking at the EXCP will not tell you if buffering has changed because it is the count of blocks processed. Set BUFNO to 1 or 8 and you will still get the same EXCP count.
If you think there is a change in SSCH for some datasets then try looking at the type 42 subtype 6 SMF records for dataset level IO metrics. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of > Jousma, David > Sent: Thursday, August 13, 2009 9:45 AM > To: IBM-MAIN@bama.ua.edu > Subject: [IBM-MAIN] Degraded I/O performance in 1.10? > > All, > > I realize this is a really open ended question. We completed our 1.8 to > 1.10 upgrade in June, with no known problems. Everything seems to be > running fine. However, I have various people(mostly developers) > occasionally complaining that they "think" the system is slower since > the upgrade. Of course, the upgrade gets blamed for everything. By > slower, the are referring to their batch jobs, those that do a lot of > I/O. > > Interestingly, several people, who do not work in the same area(and most > likely do not talk to each other), asked if file buffering has changed > somehow with the upgrade. I tell them, not that I am aware of, and ask > them for specifics to research, and in most cases I compare the jobs > running before and after the upgrade, and the EXCPs all seem to be > inline. > > So, all I can say is that there is this gut feeling that something isn't > quite right, but can't put a finger on it. > > Has anyone else noticed anything, or have idea's on what to look for? > > _________________________________________________________________ > Dave Jousma > Assistant Vice President, Mainframe Services > david.jou...@53.com > 1830 East Paris, Grand Rapids, MI 49546 MD RSCB1G > p 616.653.8429 > f 616.653.8497 > > > This e-mail transmission contains information that is confidential and may be > privileged. > It is intended only for the addressee(s) named above. If you receive this e- > mail in error, > please do not read, copy or disseminate it in any manner. If you are not the > intended > recipient, any disclosure, copying, distribution or use of the contents of > this information > is prohibited. Please reply to the message immediately by informing the sender > that the > message was misdirected. After replying, please erase it from your computer > system. Your > assistance in correcting this error is appreciated. > > > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
