On 18 March 2015 at 20:04, Vitale, Joseph <joseph.vit...@bnymellon.com> wrote:
> My Linux runs under zVM, not in a stand alone LPAR. So, NTP or STP not > required, correct ? > That depends on whether you have STP steer the clock for the LPARs. It's a priced feature. If Q TIME on z/VM is now very accurate, then you're most likely steering and your Linux guests will follow. When z/VM is not running on time, then all Linux guests will get a clock (the same) that is slightly off as well. If that bothers you (your applications rather) then you can either implement STP or have each guest synchronize it's won clock with ntpd etc. If you frequently reboot, then ntpdate during startup might be enough to stay somewhat on time (eg 3 seconds per week). Some things like Kerberos expect you to be sort-of on time (10's of seconds, iirc). My experience is that the quality of the clock with ntpd is somewhat less, but that's a moot point when it's your only option. Yes, it's true that running ntpd takes resources. But much middleware does too and we're not on G3 anymore. PS Yes, I did do an "ntpq" for CMS a while back, but the year does not have nearly enough Friday nights to come up with an alternative for STP. Rob ---------------------------------------------------------------------- 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/
