Does an OOS z13 support ICF thin provisioning with nterrupts? > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > Behalf Of Mike Schwab > Sent: Monday, March 6, 2023 1:12 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Running a Coupling Facility using a CP for a test Parallel > Sysplex 0 > anyh gotcha's? > > And this was long before Thin ICF provisioning on a CP with interrupts. > > On Mon, Mar 6, 2023 at 3:07 PM Attila Fogarasi <fogar...@gmail.com> wrote: > > > > Perhaps your outsourcer will accept recommendations by IBM in an official > > apar, see > https://urldefense.com/v3/__https://www.ibm.com/support/pages/apar/II > 09294__;!!JmPEgBY0HMszNaDT!pc-N5jQe_vQoNsN9-04ykQN3SVPA3-- > zfrRMvdLg48EaghVAdve13YxtLv7URiG7JmKVX-gL1XSkd75g6Li7Hg$ > > This says in part "If you can accept slower response times or occasional > > slower > > > > response times and the load is not too great, CFs in shared > > LPs may be a viable alternative to running CFs with DEDICATED > > CP resources." > > > > > > On Tue, Mar 7, 2023 at 12:04 AM Allan Staller < > > 00000387911dea17-dmarc-requ...@listserv.ua.edu> wrote: > > > > > Classification: Confidential > > > > > > The "spare" ICF engine on the "A" box could be shared between *your* > > > test/production sysplexes. > > > > > > HTH > > > > > > -----Original Message----- > > > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> > On Behalf > > > Of Laurence Chiu > > > Sent: Friday, March 3, 2023 9:34 PM > > > To: IBM-MAIN@LISTSERV.UA.EDU > > > Subject: Running a Coupling Facility using a CP for a test Parallel > > > Sysplex 0 anyh gotcha's? > > > > > > [CAUTION: This Email is from outside the Organization. Unless you trust > > > the sender, Don't click links or open attachments as it may be a Phishing > > > email, which can steal your Information and compromise your > Computer.] > > > > > > The situation. > > > > > > We share a couple of Z13's with another (larger client). Z13 B is where we > > > run our development LPARs and Z13 A is production. > > > > > > For critical business reasons an online application on our production LPAR > > > needs to be highly available and that means in a parallel sysplex. But > > > our > > > outsourcer has told us it cannot be done for the following reasons > because > > > there are no spare ICF engines on the host B - all are being used by other > > > CF instances, either to support production Sysplexes or development > ones > > > (not ours). > > > > > > Host A does potentially have a spare ICF engine we could use to support a > > > production parallel Sysplex but good practice does recommend you > create a > > > test one first of course. > > > > > > I then asked the question, if host A has a spare ICF engine, can't it be > > > used to support a CF to be used by the test Sysplex on B. I was advised > > > this was not possible since there are no spare connections between host > A > > > and Host B (Infiniband possibly) so the Sysplex on B could not actually > > > communicate with the CF on A. > > > > > > Our requirement for the Sysplex is primarily to be able to share a VSAM > > > dataset which is hit every time a transaction comes in with a peak of > about > > > 99tps. So we would need VSAM RLS to share the dataset records > between the > > > two application instances. There is no DB2, CICS or IMS so I think the > > > only > > > structures in the CF are those to support VSAM RLS, maybe some XCF > > > structures and core systems. > > > > > > Knowing that we would only bring up the test sysplex to make sure > > > transactions routed correctly across the two LPARs and most of the time > we > > > would have one member of the Sysplex off, I suggested that the test CF > > > could be built using a CP. To this suggestion I received the following > > > (anti) advice > > > - there would be MSU costs (we don't care since we think the MIPS load > on > > > the CF would be low). Plus we would ask that the CF be defined with > Dynamic > > > Coupling Facility Dispatch and set DYNDISP=THIN. Since that CF is going to > > > be idling most of the time, MSU consumption is not going to be a major > cost. > > > - it's strongly recommended not to do this by IBM. Yet when I read this > > > document > > > > > > > > > > https://urldefense.com/v3/__https://apc01.safelinks.protection.outlook.co > m/?url=https*3A*2F*2Fwww.ibm.com*2Fdownloads*2Fcas*2FJZB2E38Q&d > ata=05*7C01*7Callan.staller*40HCL.COM*7C1962ff1c13d7410924a708db1c61 > 7020*7C189de737c93a4f5a8b686f4ca9941912*7C0*7C0*7C6381349770666599 > 42*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzI > iLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*7C*7C*7C&sdata=78DxD9grm > MmrALQNItds2OaQ6Eyuv43mGVh5*2BoeqQnk*3D&reserved=0__;JSUlJSUlJ > SUlJSUlJSUlJSUlJSUlJSU!!JmPEgBY0HMszNaDT!pc-N5jQe_vQoNsN9- > 04ykQN3SVPA3--zfrRMvdLg48EaghVAdve13YxtLv7URiG7JmKVX- > gL1XSkd74tramVcA$ > > > the option is discussed in great detail and the only negatives are the > > > incurring of MSU costs and some performance degradation if both a z/OS > and > > > CF LPAR are trying to use the same CP at the same time. But this can be > > > managed. > > > > > > - that a CF running on a CP would need a dedicated CP engine and there > are > > > no spare engines in host B. That totally flies against the information I > > > have read from IBM docs. > > > > > > Of course for production the CF on host A would be configured to use an > > > ICF engine (or share one) > > > > > > Finally, while I accepted the argument at the time there were no > > > connections between Host A and Host B, further reading suggests that > you do > > > not need to dedicate channels for communications but use XCF or by > using > > > Infiniband sub channels or sharing the same physical link with more than > > > one Sysplex. Then the issue of running the CF on a CP goes away since I > can > > > ask for two CF's to be defined on host A, one for production and one for > > > test and DCFC ensures that that production CF is not impacted by the > > > development one. > > > > > > A lot to digest here but I really want to have some authoritative data in > > > order to refute most of the comments being our outsourcer. > > > > > > Thanks > > > > > > ---------------------------------------------------------------------- > > > For IBM-MAIN subscribe / signoff / archive access instructions, send > email > > > to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > ::DISCLAIMER:: > > > ________________________________ > > > The contents of this e-mail and any attachment(s) are confidential and > > > intended for the named recipient(s) only. E-mail transmission is not > > > guaranteed to be secure or error-free as information could be > intercepted, > > > corrupted, lost, destroyed, arrive late or incomplete, or may contain > > > viruses in transmission. The e mail and its contents (with or without > > > referred errors) shall therefore not attach any liability on the > > > originator > > > or HCL or its affiliates. Views or opinions, if any, presented in this > > > email are solely those of the author and may not necessarily reflect the > > > views or opinions of HCL or its affiliates. Any form of reproduction, > > > dissemination, copying, disclosure, modification, distribution and / or > > > publication of this message without the prior written consent of > authorized > > > representative of HCL is strictly prohibited. If you have received this > > > email in error please delete it and notify the sender immediately. Before > > > opening any email and/or attachments, please check them for viruses > and > > > other defects. > > > ________________________________ > > > > > > ---------------------------------------------------------------------- > > > For IBM-MAIN subscribe / signoff / archive access instructions, > > > send email to lists...@listserv.ua.edu with the message: INFO IBM- > MAIN > > > > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > > -- > Mike A Schwab, Springfield IL USA > Where do Forest Rangers go to get away from it all? > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
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