On Wed, Mar 18, 2015 at 10:46 AM, Vitale, Joseph <joseph.vit...@bnymellon.com> wrote: > Hello, > > Currently not running NTPD under RedHat, is that necessary or does zVM > present time adjustment via Sysplex Timer?
I think this answers that question: http://www-01.ibm.com/support/knowledgecenter/linuxonibm/com.ibm.linux.z.lgdd/lgdd_r_feature_time.html <quote> ETR- and STP-based clock synchronization Your Linux instance might be part of an extended remote copy (XRC) setup that requires synchronization of the Linux time-of-day (TOD) clock with a timing network. Linux on z Systems supports external time reference (ETR) and system time protocol (STP) based TOD synchronization. ETR and STP work independently of one another. If both ETR and STP are enabled, Linux might use either to synchronize the clock. For more information about ETR, see the IBM® Redbooks® technote at www.ibm.com/redbooks/abstracts/tips0217.html For information about STP, see www.ibm.com/systems/z/advantages/pso/stp.html Both ETR and STP support are included in the Linux kernel. No special build options are required. ETR requires at least one ETR unit that is connected to an external time source. For availability reasons, many installations use a second ETR unit. The ETR units correspond to two ETR ports on Linux. Always set both ports online if two ETR units are available. Attention: Be sure that a reliable timing signal is available before enabling clock synchronization. With enabled clock synchronization, Linux expects regular timing signals and might stop indefinitely to wait for such signals if it does not receive them. Enabling clock synchronization when booting Use kernel parameters to enable clock synchronization when booting. Enabling and disabling clock synchronization You can use the sysfs interfaces of ETR and STP to enable and disable clock synchronization on a running Linux instance. Parent topic: System resources </quote> > > Thanks > Joe -- If you sent twitter messages while exploring, are you on a textpedition? He's about as useful as a wax frying pan. 10 to the 12th power microphones = 1 Megaphone Maranatha! <>< John McKown ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
