On Tuesday, 11/25/2003 at 08:54 CST, "Allison, Phil" <[EMAIL PROTECTED]> wrote: > Is there a method to use Linux on 'Z' as an NTP Server so that We can > synchronize our w2k and unix servers to the 9037 sysplex timers. For this > purpose would there be a difference between running in LPAR versus under VM due > to differences in time offsets etc.
<disclaimer> The following was true the last time I checked. New hardware and/or software support may have been delivered since then. I still have scars from the PCICC/PCICA flap. :-) </disclaimer> Linux does not support the sysplex timer, whether in an LPAR or under VM. For small clock corrections, LPAR and virtual machine clocks will be corrected automatically by the h/w, so Linux (or any other opsys) will serve the correct time. For a sufficiently large clock correction, e.g. reestablishment of external time reference, the clock will not change and the LPAR or guest will not serve the correct time. Don't ask me what "sufficiently large" is. I don't know. But why bang on the zSeries box to get the correct time? Send those requests to the same external reference your sysplex timer is pointing to. And point your zLinux images to the same place. If you're not interested in the correct time on zLinux (not using an ETR), but simply want the discrete boxes to have the same time as zSeries, then by all means, run an (S)NTP on zLinux, whether client or server. (I'd pick the one that uses fewest cycles.) Maybe sync one guest to the outside reference and all other guests to that one guest. YMMV. Batteries not included. Alan Altmark Sr. Software Engineer IBM z/VM Development
