Subject: Re: Now why did I do that .....
From: Tony Thigpen (tony@vse2pdf.com)
Date: Fri Aug 22 2008 - 13:21:13 EDT
Fuzzy memory, but was not there a REXX phase that is required to be in the SVA to support 'something'? Now, to answer your question. Some SVA phases are really just storage blocks. Sometimes they are used because 24bit area is needed for a 31bit system task. Sometimes they are communication blocks so that different partitions can 'talk' to each other. Sometimes they are just 'easy to find' anchors to other system wide storage for system programs like schedulers or disk managers. It could also be a program called by the console command interface. Tony Thigpen -----Original Message ----- From: Tom Duerbusch Sent: 08/22/2008 01:02 PM > I just had this type of discussion with a guy from another shop. He is upgrading syncsort and we got into the who SVA thing, discussion. > > Back in the old days, before caching controllers, putting things in the SVA was a great performance boost. It eliminated the I/Os necessary to search each of the sublibraries in your temp, then perm chain (until the program was found), and eliminated the I/Os of loading the phase into storage. Back when you could do 30 I/Os per second (IBM 3350 disk drives), that was a big savings. But with caching controllers, if you are actively using many sorts, everything is cached, so why bother (if you can use the SVA storage for something else, that is). > > Now, there are still programs that need to be in the SVA because of other requirements. What are these requirements? There seems to be some phases related to the supervisor that needs to be there. As well as some phases (console stuff and open/close routines) that need to be there. > > But nowadays, why would anyone put Sort, or compiler stuff, or, for that matter REXX stuff in the SVA. In the scheme of 100 MIP processors, does it really make a difference anymore? > > Of course, the discussion centers on the 24 bit SVA. > > So, what are the reasons for loading a program in the SVA? > > Tom Duerbusch > THD Consulting > > Law of Dinner Table Attendance > > Cats must attend all meals when anything good is served. > > >>>> Tony Thigpen <tony@vse2pdf.com> 8/21/2008 10:34 PM >>> > In the past, I have removed Sort and HLASM. The phases just get loaded > into the partition when needed. Also, the trace area can be released if > you don't use SDAIDs. > > Tony Thigpen > > > -----Original Message ----- > From: Allan Peterson > Sent: 08/21/2008 06:02 PM >> With it coming up to daylight saving change time down here I'm looking >> at what else I can fit into the change window ... >> >> I need to get back about 800K out of 24bit SVA so that I can increase >> the size of my CICS regions which in turn will decrease the # of storage >> compresions >> >> We don't use the IBM REXX , but we do use FAQS/ASO (BIM) ... so why >> would I have the $SVAREXX in my SET SDL ? ? ? >> >> No ICCF >> >> >> >> Any thoughts >> >> >> >> SET SDL >> >> LIST=$SVAVTAM VTAM >> >> LIST=$SVAREXX REXX >> >> LIST=$SVAASMA HLASM >> >> LIST=$SVASORT SORT >> >> DFHALP,SVA ALLOCATION 9K >> >> DFHCCP,SVA CATALOG CONTROL 7K >> >> DFHCDDAN,SVA XRF ANCHOR >> >> DFHCSEOT,SVA EOJ CLEAN UP >> >> Etc etc etc >> >> Allan Peterson >> Network/Infrastructure Specialist Team Leader >> DDI: 09 442 8615 | Mobile: 021 750 529 | Fax: 09 442 8601 >> Email: Allan.Peterson@revera.co.nz | Web: www.revera.co.nz >> -------------------------------------------------------- >> >> WARNING:This email and any attachments contain private communications. If you are not the intended recipient, you are not entitled to read, use, disseminate, distribute or copy this email and/or its attachments (if any). If you have received this email in error, please immediately notify the sender by return email and delete this email and any attachments from your system. >> P Please consider the environment before printing this e-mail >> >> > >
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