Tommy, This sounds like the PPRC links might be a bit slow or there are not enough of them.
What do you have? Direct DASD to DASD or via a single SAN switch or even cascaded? What settings (Gbps) are all the interfaces running at (you can ask the switch for the switch and RMF for the DASD)? What type of fibre are they? LX or SX? What kind of length are they? Any queueing? There are so many variables that can affect the latency. Are there any of the above that you can improve on? I can't remember what IBM recommends but 80% sounds a little high to me. They are only used for writes (not reads). Regards, Alan Watthey -----Original Message----- From: Tommy Tsui [mailto:tommyt...@gmail.com] Sent: 15 February 2018 12:15 am Subject: DASD problem > > Hi all, Our shop found the most job elapse time prolong due to pprc synchronization versus without pprc mode. It's almost 4 times faster if without pprc synchronization. Is there any parameters we need to tune on z/os or disk subsystem side? We found the % disk util in RMF report over 80, Any help will be appreciated. Many thanks ---------------------------------------------------------------------- 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
