Jim, Thanks. That's exactly the sort of update I needed.
Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of > Jim Mulder > Sent: Thursday, February 02, 2012 10:14 AM > To: [email protected] > Subject: Re: [IBM-MAIN] Very Lage Page Datasets (was ASM and HiperPAV) > > > Another element of paging that has not been referenced is the ability > > to handle all of the swap set size in parallel. If the swap set size > > is 120 pages then the old practice was to have at least four LOCALS so > > each > thirty > > page block of pages could be swapped-in in parallel. While swapping, > like > > paging, is not as prevalent as it once was I'm wondering if the swap > > set size is still one of the principal guidelines for the number of > > locals > that > > should be defined. > > Starting with z/OS 1.8, physical swapping is no longer done at all. > Block paging has not been done for quite a while either. There can be some > trimming done for address spaces when they get logically swapped, and before > global LRU is done. So those pages might get written to contiguous slots to > help the throughput of the output I/O. But with no swapping and block paging, > they will come back in via individual page faults, with no relation to the > order in which they were written, and probably as separate I/O operations. > > I am not trying to say that is a good thing, just saying how it works now, > so that you don't spend time trying to design your paging configuration to > accommodate former behavior of the operating system. > > Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email to > [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
