> -----Original Message----- > From: The IBM z/VM Operating System > [mailto:[EMAIL PROTECTED] On Behalf Of dave > Sent: Wednesday, May 21, 2008 12:42 PM > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: z/VM, NTP, and the z/10. > > Thanks, Tom, I appreciate it. However, I would prefer not to > have to run NTP clients in each of the Linux images due to > the overhead that can produce. > > I think the point of confusion here is, at least to me, that > the z10 technical overview document seems to imply that STP > will be used to synchronize the time across LPARs and that > PR/SM will (gradually) update the hardware TOD clock in each > LAPR of a system and across systems, so that all of the > hardware clocks are kept in sync. My question is: what > happens if z/VM is running on one of those LPARs and PR/SM, > under the covers, keeps updating z/VM's hardware TOD clock? > > Or am I completely missing the point here about what STP and > NTP client features are supposed to provide? > > DJ
The instructions used by STP on a z10 only affects the TOD clock on that specific LPAR. PR/SM itself is not really involved, per se. Does z/Linux use the STCK/STCKE instructions? It's been a long time since I've looked. In any case, z/VM does not support STP at this time. I'm not too sure how it would, at least given how I __assume__ the hardware works. If it does work, then every guest would have their clock "drift" to sync with the STP server. -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology The information contained in this e-mail message may be privileged and/or confidential. It is for intended addressee(s) only. If you are not the intended recipient, you are hereby notified that any disclosure, reproduction, distribution or other use of this communication is strictly prohibited and could, in certain circumstances, be a criminal offense. If you have received this e-mail in error, please notify the sender by reply and delete this message without copying or disclosing it.
