Yeah . I got it now . Thank you Skip and Radoslaw for the clarification .
Linda On Wed, Apr 20, 2016 at 10:53 PM, Jesse 1 Robinson <[email protected]> wrote: > To reiterate Radoslaw's point, STP does not steer the clock. Rather STP > steers--synchronizes--the internal clocks of all connected CECs. STP itself > may or not be externally steered. In our case, we take an SNTP signal from > the corporate time server that is used to synchronize the entire enterprise > including Windows, UNIX, and all the other critters in the zoo. If SNTP > failed, most everyone would drift apart to some extent, but STP would still > keep connected CECs in sync with each other--a basic requirement for > parallel sysplex. > > . > . > . > J.O.Skip Robinson > Southern California Edison Company > Electric Dragon Team Paddler > SHARE MVS Program Co-Manager > 323-715-0595 Mobile > 626-302-7535 Office > [email protected] > > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of linda golding > Sent: Tuesday, April 19, 2016 2:06 AM > To: [email protected] > Subject: (External):Re: What happens with no working SE? > > Am curious . This is what i could find looking at the enhancements . Since > you say STP doesn't steer the clock , i would like to know how this works > these days . > > *http://www-03.ibm.com/systems/z/advantages/pso/stp/ntp.html > <http://www-03.ibm.com/systems/z/advantages/pso/stp/ntp.html>* > > > *Service Element (SE) Time Accuracy* > As a continuation of the zEnterprise 196 (z196) timing accuracy > improvements for an STP-only CTN, namely, SE/CPC hourly clock steer and > synch, the zEnterprise EC12 and zEnterprise BC12 have expanded these > enhancements by allowing the SE to access an STP panel-configured External > Time Source (ETS), even when the CPC is powered off or has not been IMLed. > The SE achieves this by invoking the ETS-configured NTP servers to obtain > the ETS-SE time difference and steers the SE clock towards the ETS clock. > During IML, the more accurate SE clock time transfers to the CPC clock, > maximizing the CPC timing accuracy. > > This feature is available exclusively on zEnterprise EC12 and zEnterprise > BC12. > > Thanks , > > Linda > > > > > > > > On Tue, Apr 19, 2016 at 1:57 PM, R.S. <[email protected]> > wrote: > > > W dniu 2016-04-18 o 23:19, linda golding pisze: > > > >> One of two SE failed means you can peform everything you want, > >> including STP. Maybe STP setup would be impossible (I haven't > >> checked), but I'd bet it is also possible. > >> I've been working with single SE (primary failed) for some time. It > >> wasn't my dream, but I could live with it. >>>> > >> > >> > >> I thought STP code runs on the support element . Access to the NTP > >> server from the CTS is initiated and controlled by the Support Element. > >> > >> In that case , a sysplex would die when support element is not > available . > >> > > NTP is not STP. > > STP is managed from HMC/SE but it doesn't mean the SE is steering the > > clock. > > NTP can be used for "wall clock" time adjustment, but STP will work > > without NTP at all or with NTP failure. > > Last, but not least: multi-CPC STP configuration will survive any of > > the CPC failure. Not only SE, but whole CPC. > > > > -- > > Radoslaw Skorupka > > Lodz, Poland > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
