In my opinion you may run into some interesting issues with timestamped stuff in the CFs and whatnot if the times start coming in a slightly unpredictable sequence. I don't think I'd take that risk.
When we migrated from ETR to mixed to all STP CTN, the key was two machines were ETR and had the STP feature, we had one machine that was ETR only with no STP but it was getting fed by the two ETR/STP machines. Note that we had two machines as time sources, I'm also not totally sure I'd go with one machine connected to the 9037 and rely on that. I do not believe that anything z196 and up can do ETR at all. I'm pretty sure I read that in the z196 Tech Guide redbook somewhere. (Page 14 - STP section) Thomas Ambros Operating Systems and Connectivity Engineering 518-436-6433 From: "Staller, Allan" <allan.stal...@kbmg.com> To: IBM-MAIN@LISTSERV.UA.EDU Date: 02/07/2014 09:03 Subject: Re: Sysplex Common Time Source Sent by: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> ISTR that all time references in a SYSPLEX must be within a certain tolerance (I have no recollection of the actual value). If the local time source exceeded this tolerance, the ETR (STP/9037) would guide them to the same value, or failing that , remove the system from the plex. The act of syncing the STP and the 9037 to the same time ETR might/might not provide sufficient accuracy. HTH, <snip> >That was what we originally though too, but our local IBM support >person told us we couldn't. Thinking further about configuration >activities to migrate to mixed CTN mode, I'm not seeing how on the non >STP capable processor we're going to be able to set the name of the >mixed CTN, since it isn't going to have the STP tab for that CEC, I'm not sure that that matters. IIRC, the requirement is that all systems in the sysplex get their time from the same source. As long as the z10 gets it from the timers, and there's another CEC in the CTN getting it from the same timers and acting as the primary time server for the CTN, I believe that would work. z10 <- timer zEC12 <- timer | Primary time server \/ STP other STP CECs Before STP, there was no STP tab on the HMC and the CECs were able to participate in the sysplex by virtue of using the same timer. I *think* the migration would be to make the time source the timer connected to one zEC12, make that the PTS, then add the z10 pointing to the timer. But I haven't read the fine manuals for some time, and it seems like the PTS becomes a sinle point of failure, unless at least one other machine in the CTS has a timer connection too. The point about the mixed mode CTN being envisioned as a fall-back situation, not an expected long-term situation is also good one. And if IBM is telling you "no", it's hard to argue that you'd want to try to do it. Scott </snip> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN This communication may contain privileged and/or confidential information. It is intended solely for the use of the addressee. If you are not the intended recipient, you are strictly prohibited from disclosing, copying, distributing or using any of this information. If you received this communication in error, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. This communication may contain nonpublic personal information about consumers subject to the restrictions of the Gramm-Leach-Bliley Act. You may not directly or indirectly reuse or redisclose such information for any purpose other than to provide the services for which you are receiving the information. 127 Public Square, Cleveland, OH 44114 If you prefer not to receive future e-mail offers for products or services from Key send an e-mail to mailto:dnereque...@key.com with 'No Promotional E-mails' in the SUBJECT line. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
