Just make sure that if you have a standalone CPC with CFs for that purpose that its engines are as fast as your other CPCs engines. I got into a performance problem 15 years ago when a 9674 was kept around longer that it should have been. You are only as fast as your slowest <insert appropriate component here>.
Bob -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of R.S. Sent: Wednesday, July 11, 2018 5:25 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Sysplex between two hardware Maybe it's illusory, but that is in David Raften document. Obviously it's cheaper to have 2 CPCs than 3, but it is also cheaper to have 1 CPC than 2. The white paper clearly describes some structures as demanding duplexing or third CPC with failure-isolated CF. -- Radoslaw Skorupka Lodz, Poland W dniu 2018-07-11 o 01:15, Jesse 1 Robinson pisze: > It's easy to diss a solution as 'budget' when it saves someone *else* money. > The notion that a third CEC for standalone CF is substantially better than > ICF is illusory. If you truly believe that one extra CEC is necessary, then > you really need two extra CECs for CF because there are times when you have > to take one of them down. Maybe for repair, maybe for upgrade. So you still > need a backup. > > OTOH, 'logical standalone'--interesting term--with an ICF in each z/OS CEC is > a sufficient solution. We've run this way for years and survived two separate > hard-down CEC failures with zero recovery agony. My recommendation is to run > two CECs, one substantial box to run application hosts, and a minimal > 'penalty box' just for ICFs plus a few high-cost products that bill > significantly less on a small CEC. With proper structure duplexing, you have > extraordinary redundancy at a reasonable cost. > > . > . > J.O.Skip Robinson > Southern California Edison Company > Electric Dragon Team Paddler > SHARE MVS Program Co-Manager > 323-715-0595 Mobile > 626-543-6132 Office ⇐=== NEW > robin...@sce.com > > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of R.S. > Sent: Tuesday, July 10, 2018 3:00 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: (External):Re: Sysplex between two hardware > > W dniu 2018-07-10 o 06:56, Timothy Sipples pisze: >> I should also respond to this part: >> >> Radoslaw Skorupka wrote: >>> ...for availability reasons one should avoid having CF and z/OS LPAR >>> on the same hardware, which means.... >> That's not phrased as IBM would phase it, and it's not correct as written. >> >> Even when there's some merit in physically separating the CF, the >> physical separation need only be between that CF and the particular >> z/OS Parallel Sysplex it serves. Having other z/OS LPARs, even LPARs >> that are participating in other Parallel Sysplexes, on the same >> machine as the CF is consistent with IBM's recommendations here. >> >> David Raften has published a whitepaper (updated in May, 2018) that >> explains the various CF configuration options. The direct link to the >> current edition is here: >> >> https://public.dhe.ibm.com/common/ssi/ecm/zs/en/zsw01971usen/zsw01971u >> sen-.pdf > [...] > > I quickly browsed the document and found confirmation what I learned several > years ago. > That means: > Yes, you need either standalone CF (*see note) or CF structure duplexing! > This is required for *some* structures, but ...it is. David Rften call it > structures which /require failure independence/. > > Note: Standalone CF should be understood here as LOGICAL stand alone CF. > IBM-MIAN do not allo pictures, so I'll try to describe it: > SYSPLEX PROD: > z/OS 1 in CPC A, z/OS 2 in CPC B, and CF2 in CPC B or A. And CF1 in CPC C. > Three CPCs. > However CPC C may be used for other purpose, i.e. for test LPARs. > Anything but z/OS image belonging to the sysplex PROD. > > There is also two-CPC configuration > z/OS 1 + CF1 in CPC A, z/OS 2 + CF2 in CPC B and *some structures are > duplexed*. > What I heard unofficially from IBM-ers is such configuration is "budget" > read: when you cannot afford good one. > And the link between CFs should be really local (short). > > > Note2: it is also possible to build a configuration without dedicated > (logical stand alone) CF and without duplexing. Your choice. > However it is NOT resistant to all possible (single) failures. Yes, it > is still better than parallel sysplex with single CF, but still > vulnerable to some failures. > ====================================================================== -- Treść tej wiadomości może zawierać informacje prawnie chronione Banku przeznaczone wyłącznie do użytku służbowego adresata. Odbiorcą może być jedynie jej adresat z wyłączeniem dostępu osób trzecich. Jeżeli nie jesteś adresatem niniejszej wiadomości lub pracownikiem upoważnionym do jej przekazania adresatowi, informujemy, że jej rozpowszechnianie, kopiowanie, rozprowadzanie lub inne działanie o podobnym charakterze jest prawnie zabronione i może być karalne. Jeżeli otrzymałeś tę wiadomość omyłkowo, prosimy niezwłocznie zawiadomić nadawcę wysyłając odpowiedź oraz trwale usunąć tę wiadomość włączając w to wszelkie jej kopie wydrukowane lub zapisane na dysku. This e-mail may contain legally privileged information of the Bank and is intended solely for business use of the addressee. This e-mail may only be received by the addressee and may not be disclosed to any third parties. If you are not the intended addressee of this e-mail or the employee authorized to forward it to the addressee, be advised that any dissemination, copying, distribution or any other similar activity is legally prohibited and may be punishable. If you received this e-mail by mistake please advise the sender immediately by using the reply facility in your e-mail software and delete permanently this e-mail including any copies of it either printed or saved to hard drive. mBank S.A. z siedzibą w Warszawie, ul. Senatorska 18, 00-950 Warszawa, www.mBank.pl, e-mail: kont...@mbank.plsąd Rejonowy dla m. st. Warszawy XII Wydział Gospodarczy Krajowego Rejestru Sądowego, nr rejestru przedsiębiorców KRS 0000025237, NIP: 526-021-50-88. Według stanu na dzień 01.01.2018 r. kapitał zakładowy mBanku S.A. (w całości wpłacony) wynosi 169.248.488 złotych. ---------------------------------------------------------------------- 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