On Thu, 8 Nov 2007 09:02:05 +0100, Max Scarpa <[EMAIL PROTECTED]> wrote:
>Jumping from 4 to 25 Gb isn't a good idea, but if I have 4 Gb used and 4 >unused I think there's no difference in adding, say, 2 Gb (so using 6 Gb >as total). Consider we have bursts or spikes in paging and for instance >our DB2 isn't performing well even if 'all runs well' as someone say. > If you are paging at all, then add all 4 Gb. >Anyway is there any rule of thumb, having z/OS 1.7, for max central >storage ? I mean, is there a suggested value to avoid RSM overhead before >z/OS 1.8 (1 Gb ? 5, 10 or which value for central storage) ? > I don't think there is an ROT, just the warning that if you aren't paging at all, don't add gobs of storage "just because". A few GB isn't going to be noticeable or measurable. No need to micro-manage. It also isn't going to matter unless you are running at or near 100% busy and you want to squeeze every last cycle out of the machine that you can. I say this because a lot of shops do run that way. 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