Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
Mike, Excuse my flippant reply earlier. Are you confusing "one frame at a time" with ESCON's path ownership and "one IO at a time?" Both ESCON and Fiber Channel use receiving buffers and ACK responses to control the number of in-flight frames, or DIBs in the channel. Both protocols will send frames until the frames in flight is equal to the number of buffers that the receiving port can handle. The transmitter then waits for an ACK from the receiver before sending the next frame. If there are enough buffers for the link to be full of frames end-to-end across the distance, then data streams continuously from port to port. ESCON cannot match the throughput of multiple IO on a channel, but that is not an architectural limitation caused by the number of ESCON data buffers or Fiber Channel buffer credits. My memory may be hazy on this, but I think a lost frame on ESCON would cause retransmission of all the frames in an IO. I need to find Dr Pat's old DIB paper. Ron -Original Message- From: ronjhawk...@sbcglobal.net Sent: Friday, June 8, 2018 4:17 PM To: 'IBM Mainframe Discussion List' Subject: RE: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC Mike, Then how did ESCON use data buffers for flow control? Ron -Original Message- From: IBM Mainframe Discussion List On Behalf Of Mike Schwab Sent: Friday, June 8, 2018 3:29 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC ESCON is synchronous, where after sending a buffer, it would wait for acknowledgement before sending the next buffer. FICON is async, where it sends buffer after buffer without waiting. If it doesn't get an acknowledgement within a certain time frame it would resend the lost buffer. On Fri, Jun 8, 2018 at 5:15 PM Ron hawkins wrote: > > Radslaw, > > Have you confused a few things when explaining the difference between > synchronous and asynchronous, and ESCON compared to FICON? > > Buffer credits are synonymous to DIBs, and a large number of buffer credits > provided by Fiber Channel switches allowed the connection to be full of > frames end to end over a greater distance than FICON. > > The buffer credits, however, did not have anything to do with reducing the > RTD spent in the "talking" as you put it. That is purely a function of two > round trips required by Fiber channel compared to 9 (I think) required by > ESCON. Buffer credits and number of DIBs affected transfer rate, not RTD. > > Asynchronous remote copy still requires the provision of adequate buffer > credits over distance to maintain line speed, where the number is a function > of line speed and distance. Having no distance related impact on response > time at any distance is the advantage of asynchronous. Synchronous cannot > guarantee zero data loss, so I struggle with coming up with advantages beyond > that myth. > > Ron > > > -Original Message- > From: IBM Mainframe Discussion List On Behalf Of > R.S. > Sent: Friday, June 8, 2018 3:11 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC > > 1. PPRC-XD and PPRC are very different animals. PPRC-XD is capable to work on > any distance, while PPRC is limited by speed of light which is not planned to > change. > 2. ESCON vs FICON did huge difference not only in speed (bit per second), but > also in something called credit buffers. In very simple word A talks to B, > but A can say many words before B acknowledge it. > Many words can be "in transit", which makes the protocol quite independend on > link length. This is better visible when A is host and B is CU (DASD or tape). > > -- > Radoslaw Skorupka > Lodz, Poland > > > > > > > W dniu 2018-06-08 o 06:10, Sankaranarayanan, Vignesh pisze: > > 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:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Jesse 1 Robinson > > Sent: Thursday 07-Jun-2018 23:52 > > To: IBM-MAIN@LISTSERV.UA.EDU > > 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
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
Mike, Then how did ESCON use data buffers for flow control? Ron -Original Message- From: IBM Mainframe Discussion List On Behalf Of Mike Schwab Sent: Friday, June 8, 2018 3:29 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC ESCON is synchronous, where after sending a buffer, it would wait for acknowledgement before sending the next buffer. FICON is async, where it sends buffer after buffer without waiting. If it doesn't get an acknowledgement within a certain time frame it would resend the lost buffer. On Fri, Jun 8, 2018 at 5:15 PM Ron hawkins wrote: > > Radslaw, > > Have you confused a few things when explaining the difference between > synchronous and asynchronous, and ESCON compared to FICON? > > Buffer credits are synonymous to DIBs, and a large number of buffer credits > provided by Fiber Channel switches allowed the connection to be full of > frames end to end over a greater distance than FICON. > > The buffer credits, however, did not have anything to do with reducing the > RTD spent in the "talking" as you put it. That is purely a function of two > round trips required by Fiber channel compared to 9 (I think) required by > ESCON. Buffer credits and number of DIBs affected transfer rate, not RTD. > > Asynchronous remote copy still requires the provision of adequate buffer > credits over distance to maintain line speed, where the number is a function > of line speed and distance. Having no distance related impact on response > time at any distance is the advantage of asynchronous. Synchronous cannot > guarantee zero data loss, so I struggle with coming up with advantages beyond > that myth. > > Ron > > > -Original Message- > From: IBM Mainframe Discussion List On Behalf Of > R.S. > Sent: Friday, June 8, 2018 3:11 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC > > 1. PPRC-XD and PPRC are very different animals. PPRC-XD is capable to work on > any distance, while PPRC is limited by speed of light which is not planned to > change. > 2. ESCON vs FICON did huge difference not only in speed (bit per second), but > also in something called credit buffers. In very simple word A talks to B, > but A can say many words before B acknowledge it. > Many words can be "in transit", which makes the protocol quite independend on > link length. This is better visible when A is host and B is CU (DASD or tape). > > -- > Radoslaw Skorupka > Lodz, Poland > > > > > > > W dniu 2018-06-08 o 06:10, Sankaranarayanan, Vignesh pisze: > > 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:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Jesse 1 Robinson > > Sent: Thursday 07-Jun-2018 23:52 > > To: IBM-MAIN@LISTSERV.UA.EDU > > 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 > > robin...@sce.com > > > > > > -Original Message- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > > Behalf Of R.S. > > Sent: Thursday, June 07, 2018 4:10 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > 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 > > > > > >
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
ESCON is synchronous, where after sending a buffer, it would wait for acknowledgement before sending the next buffer. FICON is async, where it sends buffer after buffer without waiting. If it doesn't get an acknowledgement within a certain time frame it would resend the lost buffer. On Fri, Jun 8, 2018 at 5:15 PM Ron hawkins wrote: > > Radslaw, > > Have you confused a few things when explaining the difference between > synchronous and asynchronous, and ESCON compared to FICON? > > Buffer credits are synonymous to DIBs, and a large number of buffer credits > provided by Fiber Channel switches allowed the connection to be full of > frames end to end over a greater distance than FICON. > > The buffer credits, however, did not have anything to do with reducing the > RTD spent in the "talking" as you put it. That is purely a function of two > round trips required by Fiber channel compared to 9 (I think) required by > ESCON. Buffer credits and number of DIBs affected transfer rate, not RTD. > > Asynchronous remote copy still requires the provision of adequate buffer > credits over distance to maintain line speed, where the number is a function > of line speed and distance. Having no distance related impact on response > time at any distance is the advantage of asynchronous. Synchronous cannot > guarantee zero data loss, so I struggle with coming up with advantages beyond > that myth. > > Ron > > > -Original Message- > From: IBM Mainframe Discussion List On Behalf Of > R.S. > Sent: Friday, June 8, 2018 3:11 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC > > 1. PPRC-XD and PPRC are very different animals. PPRC-XD is capable to work on > any distance, while PPRC is limited by speed of light which is not planned to > change. > 2. ESCON vs FICON did huge difference not only in speed (bit per second), but > also in something called credit buffers. In very simple word A talks to B, > but A can say many words before B acknowledge it. > Many words can be "in transit", which makes the protocol quite independend on > link length. This is better visible when A is host and B is CU (DASD or tape). > > -- > Radoslaw Skorupka > Lodz, Poland > > > > > > > W dniu 2018-06-08 o 06:10, Sankaranarayanan, Vignesh pisze: > > 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:IBM-MAIN@LISTSERV.UA.EDU] On > > Behalf Of Jesse 1 Robinson > > Sent: Thursday 07-Jun-2018 23:52 > > To: IBM-MAIN@LISTSERV.UA.EDU > > 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 > > robin...@sce.com > > > > > > -Original Message- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > > Behalf Of R.S. > > Sent: Thursday, June 07, 2018 4:10 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > 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 lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > > MARKSANDSPENCER.COM > > > > Unless otherwise stated above: > > Marks and Spencer
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
Radslaw, Have you confused a few things when explaining the difference between synchronous and asynchronous, and ESCON compared to FICON? Buffer credits are synonymous to DIBs, and a large number of buffer credits provided by Fiber Channel switches allowed the connection to be full of frames end to end over a greater distance than FICON. The buffer credits, however, did not have anything to do with reducing the RTD spent in the "talking" as you put it. That is purely a function of two round trips required by Fiber channel compared to 9 (I think) required by ESCON. Buffer credits and number of DIBs affected transfer rate, not RTD. Asynchronous remote copy still requires the provision of adequate buffer credits over distance to maintain line speed, where the number is a function of line speed and distance. Having no distance related impact on response time at any distance is the advantage of asynchronous. Synchronous cannot guarantee zero data loss, so I struggle with coming up with advantages beyond that myth. Ron -Original Message- From: IBM Mainframe Discussion List On Behalf Of R.S. Sent: Friday, June 8, 2018 3:11 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC 1. PPRC-XD and PPRC are very different animals. PPRC-XD is capable to work on any distance, while PPRC is limited by speed of light which is not planned to change. 2. ESCON vs FICON did huge difference not only in speed (bit per second), but also in something called credit buffers. In very simple word A talks to B, but A can say many words before B acknowledge it. Many words can be "in transit", which makes the protocol quite independend on link length. This is better visible when A is host and B is CU (DASD or tape). -- Radoslaw Skorupka Lodz, Poland W dniu 2018-06-08 o 06:10, Sankaranarayanan, Vignesh pisze: > 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:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of Jesse 1 Robinson > Sent: Thursday 07-Jun-2018 23:52 > To: IBM-MAIN@LISTSERV.UA.EDU > 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 > robin...@sce.com > > > -Original Message- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of R.S. > Sent: Thursday, June 07, 2018 4:10 AM > To: IBM-MAIN@LISTSERV.UA.EDU > 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 lists...@listserv.ua.edu 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. > > == -- 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
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
1. PPRC-XD and PPRC are very different animals. PPRC-XD is capable to work on any distance, while PPRC is limited by speed of light which is not planned to change. 2. ESCON vs FICON did huge difference not only in speed (bit per second), but also in something called credit buffers. In very simple word A talks to B, but A can say many words before B acknowledge it. Many words can be "in transit", which makes the protocol quite independend on link length. This is better visible when A is host and B is CU (DASD or tape). -- Radoslaw Skorupka Lodz, Poland W dniu 2018-06-08 o 06:10, Sankaranarayanan, Vignesh pisze: 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:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Jesse 1 Robinson Sent: Thursday 07-Jun-2018 23:52 To: IBM-MAIN@LISTSERV.UA.EDU 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 robin...@sce.com -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of R.S. Sent: Thursday, June 07, 2018 4:10 AM To: IBM-MAIN@LISTSERV.UA.EDU 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 lists...@listserv.ua.edu 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. == -- 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 025237, NIP: 526-021-50-88. Według stanu na dzień 01.01.2018 r. kapitał zakładowy mBanku S.A. (w całości wpłacony) wynosi
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
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:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Jesse 1 Robinson Sent: Thursday 07-Jun-2018 23:52 To: IBM-MAIN@LISTSERV.UA.EDU 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 robin...@sce.com -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of R.S. Sent: Thursday, June 07, 2018 4:10 AM To: IBM-MAIN@LISTSERV.UA.EDU 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 lists...@listserv.ua.edu 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 lists...@listserv.ua.edu with the message: INFO IBM-MAIN
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
Hi Jerry, Replication over IP is really cool and simple; I suppose it needs the same trick to make the TDMF copy consistent as is required for PPRC-XD (quiescing all workload), in TDMF's case because it's host-based. Let's say ther's channel extension between A <-> B, and PPRC / PPRC-XD is used. After the migration to B, we can still use the path as a DR pathway to fail back, but with TDMF; there's no DR option available for Day-1. So DR (basically vol replication) should have been already planned at site B before moving volumes over yonder. - Vignesh Mainframe Infrastructure -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Jerry Whitteridge Sent: Thursday 07-Jun-2018 21:53 To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC We have always used TDMF as it's a vendor neutral solution. Jerry Whitteridge Delivery Manager / Mainframe Architect GTS - Safeway Account 602 527 4871 Mobile jerry.whitteri...@ibm.com IBM Services IBM Mainframe Discussion List wrote on 06/07/2018 01:36:55 AM: > From: Ron hawkins > To: IBM-MAIN@LISTSERV.UA.EDU > Date: 06/07/2018 01:37 AM > Subject: Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC Sent by: IBM > Mainframe Discussion List > > Vignesh, > > Only XRC (Global whatever for z/OS) supports migration between > vendors, and > go home only works between Hitachi and IBM (or does EMC support XRC now). > > Hitachi and EMC have their own FICON based migration utilities, but I > am not > sure about IBM. > > There are host software options for migration like FDR/PAS and TDMF. > > Ron > > -Original Message- > From: IBM Mainframe Discussion List On > Behalf Of > Sankaranarayanan, Vignesh > Sent: Wednesday, June 6, 2018 9:23 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC > > Thanks Lizette. > How about using them in the context of migrating b/w IBM boxes or IBM > to other vendors, or other vendors to IBM. > What's supported, what's not, etc. ? > > - Vignesh > Mainframe Infrastructure > > -Original Message- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] > On Behalf Of Lizette Koehler > Sent: Thursday 07-Jun-2018 01:20 > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: [EXTERNAL] Re: PPRC-XD vs Async PPRC > > Have you done any internet searches with the phrase > > > PPRC-XD vs Async PPRC > > I found many hits doing that. > > Otherwise - could provide more detail of what type of information you > are looking for. > > > Lizette > > > > -Original Message- > > From: IBM Mainframe Discussion List On > > Behalf Of Sankaranarayanan, Vignesh > > Sent: Wednesday, June 06, 2018 9:18 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: PPRC-XD vs Async PPRC > > > > 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.. ? > > > > - Vignesh > > Mainframe Infrastructure > > > > > > 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 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 > > -- > 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
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
We have always used TDMF as it's a vendor neutral solution. Jerry Whitteridge Delivery Manager / Mainframe Architect GTS - Safeway Account 602 527 4871 Mobile jerry.whitteri...@ibm.com IBM Services IBM Mainframe Discussion List wrote on 06/07/2018 01:36:55 AM: > From: Ron hawkins > To: IBM-MAIN@LISTSERV.UA.EDU > Date: 06/07/2018 01:37 AM > Subject: Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC > Sent by: IBM Mainframe Discussion List > > Vignesh, > > Only XRC (Global whatever for z/OS) supports migration between vendors, and > go home only works between Hitachi and IBM (or does EMC support XRC now). > > Hitachi and EMC have their own FICON based migration utilities, but I am not > sure about IBM. > > There are host software options for migration like FDR/PAS and TDMF. > > Ron > > -Original Message- > From: IBM Mainframe Discussion List On Behalf Of > Sankaranarayanan, Vignesh > Sent: Wednesday, June 6, 2018 9:23 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC > > Thanks Lizette. > How about using them in the context of migrating b/w IBM boxes or IBM to > other vendors, or other vendors to IBM. > What's supported, what's not, etc. ? > > - Vignesh > Mainframe Infrastructure > > -Original Message- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of Lizette Koehler > Sent: Thursday 07-Jun-2018 01:20 > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: [EXTERNAL] Re: PPRC-XD vs Async PPRC > > Have you done any internet searches with the phrase > > > PPRC-XD vs Async PPRC > > I found many hits doing that. > > Otherwise - could provide more detail of what type of information you are > looking for. > > > Lizette > > > > -Original Message- > > From: IBM Mainframe Discussion List On > > Behalf Of Sankaranarayanan, Vignesh > > Sent: Wednesday, June 06, 2018 9:18 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: PPRC-XD vs Async PPRC > > > > 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.. ? > > > > - Vignesh > > Mainframe Infrastructure > > > > > > 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 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 > > -- > 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 > -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
Vignesh, Only XRC (Global whatever for z/OS) supports migration between vendors, and go home only works between Hitachi and IBM (or does EMC support XRC now). Hitachi and EMC have their own FICON based migration utilities, but I am not sure about IBM. There are host software options for migration like FDR/PAS and TDMF. Ron -Original Message- From: IBM Mainframe Discussion List On Behalf Of Sankaranarayanan, Vignesh Sent: Wednesday, June 6, 2018 9:23 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: [IBM-MAIN] [EXTERNAL] Re: PPRC-XD vs Async PPRC Thanks Lizette. How about using them in the context of migrating b/w IBM boxes or IBM to other vendors, or other vendors to IBM. What's supported, what's not, etc. ? - Vignesh Mainframe Infrastructure -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Lizette Koehler Sent: Thursday 07-Jun-2018 01:20 To: IBM-MAIN@LISTSERV.UA.EDU Subject: [EXTERNAL] Re: PPRC-XD vs Async PPRC Have you done any internet searches with the phrase PPRC-XD vs Async PPRC I found many hits doing that. Otherwise - could provide more detail of what type of information you are looking for. Lizette > -Original Message- > From: IBM Mainframe Discussion List On > Behalf Of Sankaranarayanan, Vignesh > Sent: Wednesday, June 06, 2018 9:18 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: PPRC-XD vs Async PPRC > > 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.. ? > > - Vignesh > Mainframe Infrastructure > > > 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 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 -- 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
Re: [EXTERNAL] Re: PPRC-XD vs Async PPRC
Thanks Lizette. How about using them in the context of migrating b/w IBM boxes or IBM to other vendors, or other vendors to IBM. What's supported, what's not, etc. ? - Vignesh Mainframe Infrastructure -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Lizette Koehler Sent: Thursday 07-Jun-2018 01:20 To: IBM-MAIN@LISTSERV.UA.EDU Subject: [EXTERNAL] Re: PPRC-XD vs Async PPRC Have you done any internet searches with the phrase PPRC-XD vs Async PPRC I found many hits doing that. Otherwise - could provide more detail of what type of information you are looking for. Lizette > -Original Message- > From: IBM Mainframe Discussion List On > Behalf Of Sankaranarayanan, Vignesh > Sent: Wednesday, June 06, 2018 9:18 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: PPRC-XD vs Async PPRC > > 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.. ? > > - Vignesh > Mainframe Infrastructure > > > 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 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 -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
