Thanks for the thoughtful analysis. Our excessive caution stems from our being novices with PPRC and the fact that we're doing production this time. We did the DR site a while back knowing that any discrepancy could be overwritten by XRC mirroring.
Most folks seem to think that we're being a little silly, which is actually reassuring. We have T's of volumes and a limited window. I did get one off-list offer of a product that that sounds pretty great, but we may just suck it up pretend we're grownups. 😉 . . 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 <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of R.S. Sent: Wednesday, April 24, 2019 8:40 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: (External):Re: Volume compare utility Indeed, such tool is usually not needed, it is enough to know the copy service ended with RC=0. It can be FlashCopy, TF/Clone, SRDF, PPRC, XRC, Shadowimage. One see the job finished with not errors so he's pretty sure that source and target volumes are the same. However let's assume the copy was performed week ago, by Frankie. And Frankie is out of office. How can we be sure volume A has exactly the same content as volume B? There several ways: a) use some tool which Jesse asked about (however I don't know any). b) perform the copy again just to create new copy. Sounds overkill, but the tool above would generate at least the same I/O. c) create dump of both volumes and compare them i.e. using some hash function. Even more I/O and CPU cycles. The advantage is the volumes can be online to different system (local and remote) and each of them compute its own hash for comparison. At the time of verification no connectivity between local and remote DASD is required. My €0.02 -- Radoslaw Skorupka Lodz, Poland W dniu 2019-04-23 o 22:13, Laurence Chiu pisze: > We are about to replace our DS8870 in the DR site with a new DS8886. This > is currently in a Metro Mirror relationship with production. We will copy > from the old SAN to the new SAN using Global Copy and then start a Metro > Mirror session from the production SAN to the new SAN. This is all using > Copy Services Manager. I must admit nobody has ever considered having to do > a track compare following the copy since that means you don't think any of > the copy services manager copy products have sufficient checking in them. > > This is especially true when we regularly flash copy from our production > copy to a third copy and IPL our host from them. > > On Tue, Apr 23, 2019, 11:52 AM Jesse 1 Robinson <jesse1.robin...@sce.com> > wrote: > >> Sorry for not taking the time to search the archives for this. We're >> shortly moving from one DS8 DASD subsystem to another via global mirroring >> (PPRC). We have the process worked out, but we're looking for the quickest >> possible way to verify that the copy of a volume is identical to the >> original. Systems will be down for the duration, so a utility that will >> simply compare two volumes-for example track by track-in the shortest >> elapsed time will win. On account of systems being down. >> >> Of course the deadline is looming. TIA. >> >> . >> . >> 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<mailto:robin...@sce.com> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
