Denis Heidtmann wrote: > This AM the log showed an offset of 0.366 seconds, so it looks like > the hardware clock was reset. Is it possible that the hardware clock > is reset (on shutdown) to the nearest second? That would account for > the offsets bouncing around, but staying under 1 second. Here's an excellent article on system clock, hardware clock, and NTP. https://wiki.ubuntu.com/HardwareClock
What I gleaned from it: The OS stores(shutdown) and retrieves(bootup) system time from the hardware clock. At bootup after the system clock is set per the hw clock, it's going to query an NTP server via ntpdate for a more accurate time setting. Although the hw clock can keep time, it's not as accurate as any level of stratum (1-4) clock. It "free runs" w/o a reference source. So I would expect small stepping like this to occur, especially if you're only syncing the time once a day. * Interesting factoid: A GPS receiver can be used as a Stratum 1 clock source. _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
