Serge Bets wrote: > On Tuesday, January 22, 2008 at 19:02:23 +0000, Dean S. Messing wrote: > > > Is it possible to disable "11 minute mode" from "ntp.conf"? > > No. You have to tweak the kernel. If you have the PPSkit: > > | $ echo 0 > /proc/sys/kernel/time/rtc_update > > Otherwise you have to patch time.c in the kernel. Dead easy, just a > matter of commenting out a line or two. I'm so patching all my kernels, > reading and writing the RTC exclusively with hwclock 2.31, and am > getting a far better accuracy. > > The main purpose of an RTC is to initialise the system time at powerup, > isn't it? Most people startup in the morning at around half a second of > the true time, and later ntpd has to step this to UTC. I routinely > startup at some low milliseconds of the true time, offset quickly > slewed. My last step event was years ago.
Thanks Serge. I looked up PPSkit. Looks good, but I'm going to have to learn how to patch the Fedora kernel to install PPSkit. But I'm discovering that I have rather deeper problems on my machine (a Dell 490 Precision). Using adjtimex --compare to track the drift between system and cmos clock (ntpd not running), I see that the RTC is behaving _very_ strangely. It will begin to return screwy values after several hours of doing "adjtimex --compare" and then get to the point where "hwclcok --show" hangs. So my desire to turn off "11 minute mode" is mute when ntp is running is mute. For your amusement, here's a snippet of the output of "adjtime --compare" with an interval of 60 seconds: 1200982902 0.001784 -2.0 10001 3929312 10001 4060301 1200982962 0.001792 0.1 10001 3929312 10001 3920719 1200983022 0.002051 4.3 10001 3929312 10001 3646240 1200983082 0.001828 -3.7 10001 3929312 10001 4173062 1200983142 0.001756 -1.2 10001 3929312 10001 4007957 1200983202 0.002025 4.5 10001 3926656 10001 3632906 1200983261 0.500370 8305.8 10001 3926288 9918 3549307 1200983281 40.001689 658355.3 10001 3926288 3418 301130 1200983341 40.001931 4.0 10001 3926288 10001 3661966 1200983407 34.001894 -100000.6 10001 3926288 11001 3966652 1200983461 40.001646 99995.9 10001 3926288 9001 4197121 1200983521 40.001890 4.1 10001 3926288 10001 3659882 1200983609 12.001763 -466668.8 10001 3924640 14668 1878649 1200983641 40.001606 466664.0 10001 3924640 5334 6280787 1200983741 0.001726 -666664.7 10001 3924640 16668 1609118 1200983761 40.001911 666669.8 10001 3924640 3334 5907090 1200983821 40.001553 -6.0 10001 3924640 10001 4315525 1200983921 0.001748 -666663.4 10001 3924640 16668 1527086 1200983941 40.001894 666669.1 10001 3924640 3334 5949798 1200984001 40.001554 -5.7 10001 3924640 10001 4295994 1200984101 0.001700 -666664.2 10001 3921488 16668 1577580 1200984161 0.001291 -6.8 10001 3921104 10001 4367718 1200984221 0.001532 4.0 10001 3921104 10001 3657823 1200984275 6.001806 100004.6 10001 3921104 9001 3621886 1200984301 40.001722 566665.3 10001 3920368 4334 6196568 1200984361 40.001974 4.2 10001 3920368 10001 3645108 1200984427 34.001868 -100001.8 10001 3920368 11001 4036253 1200984481 40.001679 99996.8 10001 3920368 9001 4126878 Things got so bad that the output eventually became: 199345540 1001658696.064552 1592732.9 10001 3879376 -5926 1725431 199345717 1001658600.500585 -1592732.8 10001 3879376 25928 6027853 199345718 1001658696.023830 1592054.1 10001 3879376 -5919 335126 199345896 1001658600.500586 -1592054.1 10001 3879376 25922 868985 199345897 1001658696.045414 1592413.8 10001 3879376 -5923 2975047 Before it went crazy, it had run smoothly for 5 or 6 hours. When I rebooted into the BIOS and looked at the RTC it was off by several years. This has now happened thrice, but only when adjtimex is running in the compare mode for long periods. I have no idea what this means. The cmos battery does not appear to be the problem since, after a reboot, the RTC remains at proper time indefinitely (modulo drift), unless and until I run adjtimex --compare for several hours. Anyway, thanks for the info. on "11 minute mode". Wish I could fix my RTC problem Dean _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
