From a RedBook I just downloaded (Server Time Protocol Planning Guide sg247280.pdf).
"The z/VM(r) operating system does not support STP or the Sysplex Timer. It can, however, tolerate their existence. That is, if z/VM is running on an STP-enabled server or on a server attached to the Sysplex Timer, z/VM continues to operate normally and has no awareness of STP or the Sysplex Timer. The servers TOD is synchronized to STP or the Sysplex Timer by the LPAR LIC. The logical partition has a logical TOD offset from the processor TOD, which may be set by z/VM during IPL. If a synchronization check occurs, the LPAR LIC adjusts the logical TOD offset for each logical partition. To zero out the offset, the logical partition must be deactivated and activated again." Paul Feller AIT Mainframe Technical Support [EMAIL PROTECTED] (319)-355-7824 -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Richards.Bob Sent: Wednesday, October 11, 2006 10:49 AM To: [email protected] Subject: Re: Server Time Protocol support for zSeries I'm confused as well. And it has been awhile since I played with this (early days of sysplex timers, ETR, et al.) Doesn't the z9 have a *hardware* clock *AND* a TOD clock? And isn't the hardware clock be set by the Sysplex timer? In addition to John's NTP daemon idea, can't z/VM get its time from the hardware clock and subsequently z/Linux underneath z/VM? Or am I wrong about the hardware clock and the rest is my personal pipe dream? :-( Bob Richards -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of McKown, John Sent: Wednesday, October 11, 2006 11:41 AM To: [email protected] Subject: Re: Server Time Protocol support for zSeries > -----Original Message----- > From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of > Dave Jones > Sent: Wednesday, October 11, 2006 10:31 AM > To: [email protected] > Subject: Re: Server Time Protocol support for zSeries > > > That's a good question, John. As far as I know, Linux on zSeries > (either VM guest or native) can use an external time source to set its > clock. > > The real problem is that z/VM and it's guests can not use the same > time source as z/OS to sync their clocks together. Consider the case > where there are two LPARS in a z9-BC, one running z/OS and using STP > to set its clock and the other LPAR running z/VM and Linux guests with > its time set by the operator's Timex. :-) > > DJ I'm still a bit confused. I know that z/VM cannot set its clock to the STP time source. But why couldn't the Linux systems under z/VM use XNTP to set their clock to the z/OS value? z/OS 1.7 can run an NTP daemon which the Linux instances should be able to use. I hope that would be "close enough". -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology This message (including any attachments) contains confidential information intended for a specific individual and purpose, and its content is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this transmission, or taking any action based on it, is strictly prohibited. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 LEGAL DISCLAIMER The information transmitted is intended solely for the individual or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of or taking action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you have received this email in error please contact the sender and delete the material from any computer. Seeing Beyond Money is a service mark of SunTrust Banks, Inc. [ST:XCL] ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
