On Tue, 7 Apr 2009 15:10:11 -0400, Lizette Koehler <[email protected]> wrote:
>I am currently working with our DB2 group on a problem that requires an SVC dump. IBM is asking for us to set maxspace to 8g. I only have 8g real memory on this lpar. We currently have maxspace set to 2.5G. > >What would be my impact if I set the maxspace to 8G on an LPAR with only 8G real memory. That could cause a problem. I probably wouldn't set it to more than half my real storage... but I've never done any testing. I'm sure it depends on how many page data sets you have, the speed / type of dasd, how many paths etc. ISTR an APAR not too long that may have tried to help prevent aux storage shortages related to SVCDUMPs... but that could have been from multiple SVC dumps or I could just be dreaming. >Will that cause me any problems or overhead? How can I calculate what I will really need for this DB2 system to dump? > I guess you can start by looking at the real frames shown in SDSF or RMF III. If you received a partial dump with 2.5G, perhaps (during off hours) set MAXSPACE to 4G and take a console dump to see how you fair. On a similar / related note: What does your paging and paging configuration look like today if you are running large address spaces like that with only 8G real memory? Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America / Farmers Insurance Group - ZFUS G-ITO mailto:[email protected] z/OS Systems Programming expert at http://expertanswercenter.techtarget.com/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html ---------------------------------------------------------------------- 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
