Hi Skip, Looks like you tried PPRC over "long distance" and had a bad exp back then. PPRC-XD should work fine for actual long distance, assuming that the LPAR itself can get an outage to let the final delta synchronize.
– Vignesh Mainframe Infrastructure -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Jesse 1 Robinson Sent: Thursday 07-Jun-2018 23:52 To: [email protected] Subject: [EXTERNAL] Re: PPRC-XD vs Async PPRC Data consistency was one of two reasons we chose circa 2000 to use XRC rather than PPRC. I know the technology has changed, and I've been *told* that PPRC is now capable of maintaining consistency, but I have not seen it in action. The other reason for XRC BTW was the synchronizing problem: we could not tolerate the I/O delay waiting for remote confirmation from 120 KM via ESCON. In 2000, everything was slower. Now we use DWDM via FICON. . . 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 [email protected] -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of R.S. Sent: Thursday, June 07, 2018 4:10 AM To: [email protected] Subject: (External):Re: PPRC-XD vs Async PPRC W dniu 2018-06-06 o 18:18, Sankaranarayanan, Vignesh pisze: > Hello All, > > Please could you point me to any doc explaining the differences between the 2. > Any important, obscure, techdocs or KB page or some such as well.. ? Fundamental difference is data consistency. PPRC-XD is *inconsistent* copy during most of the time. Inconsistent is unusable. You have to quiesce the production and wait a little until the delta become zero (the copy become consistent). Asynchronous copy like XRC, SRDF/A, HARC is different. It is *consistent* copy - data on secondary site is usable, but is not current. Of course the time delta is small, but the most important is you don't have later data while earlier data is missing. -- Radoslaw Skorupka Lodz, Poland ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN MARKSANDSPENCER.COM ________________________________ Unless otherwise stated above: Marks and Spencer plc Registered Office: Waterside House 35 North Wharf Road London W2 1NW Registered No. 214436 in England and Wales. Telephone (020) 7935 4422 Facsimile (020) 7487 2670 www.marksandspencer.com Please note that electronic mail may be monitored. This e-mail is confidential. If you received it by mistake, please let us know and then delete it from your system; you should not copy, disclose, or distribute its contents to anyone nor act in reliance on this e-mail, as this is prohibited and may be unlawful. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
