Thanks, Dave, but I determined that VLF is not active for this data set. There are some LOADs being issued for system modules that are being resolved out of LPA and the LINKLST, but the STEPLIB directories are, of course, scanned for them first. At this point, it appears that although the PDSE directories are cached over in the SMSPDSE address space, and *no* I/O is actually done against the data set, there are some "EXCPs" charged against the first PDSE in the STEPLIB concatenation for the directory scans.
This is all happening in a large ISV product with dozens of load modules, so its a little hard to come to any really solid conclusions. When I get a chance, I'll write a little test program to isolate the circumstances as I understand them now, and see if it happens there as well. For now, the Customer is satisfied that there are not a lot of redundant or unnecessary LOADs occurring, so the importance of the issue has diminished. --Art At 02:39 PM 7/27/2007, Dave Barry wrote: >Are you SMS-caching the PDSE? See APARS II14026 OA15322 for hints. > >db > >-----Original Message----- >From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On >Behalf Of Art Celestini >Sent: Thursday, July 26, 2007 2:01 PM >To: [email protected] >Subject: VLF Question > > >I have a situation where there are high "EXCP" counts against a PDSE >STEPLIB, but a GTF trace of the target volume shows no actual I/O. Does >anyone know whether VLF accumulates "fake" EXCPs, perhaps to >reflect what would be the case if it (VLF) wasn't active? > >Thanks, >Art ================================================== Art Celestini Celestini Development Services Phone: 201-670-1674 Wyckoff, NJ ============= http://celestini.com ============= Mail sent to the "From" address used in this post will be rejected by our server. Please send off- list email to: ibmmain<at-sign>celestini<dot>com. ================================================== ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
