I have dug into this more, and found that when clock setting changes to "Automatically" the script /etc/network/if-up.d/ntpdate is triggered and in the end the command
/usr/sbin/ntpdate -s ntp.ubuntu.com is executed. When this happens, I have seen TWO very different kinds of errors, the same in *mako, arale, and frieza*. These are: *** ONE ntpdate fails to resolve DNS names or cannot connect to servers. I see traces in syslog like: ntpdate[1571]: name server cannot be used: Temporary failure in name resolution (-3) ntpdate[2599]: no server suitable for synchronization found However, when I execute ntpdate from the command line ( /usr/sbin/ntpdate -d -s ntp.ubuntu.com ) things look good, and I can browse too. This error usually goes away after switching on/off flight mode (as in the bug description) or rebooting. It seems an error in networking configuration. *** TWO When ntpdate can connect to the servers, it is not always able to set the right date/time, and it depends on how deviated we are from real time: - If we have set manually the date/time to the past, it works fine (at least for values of less that a decade) - If we have set manually the date/time to the future, ntpdate is able to correct it if we are just a few hours in the future, but it fails to change the time if the deviation is one day or more. The error that appears in syslog is: ntpdate[4809]: Can't adjust the time of day: Invalid argument which seems to happen because ntptime is calling adjtime() glibc function with values that are much bigger than the theoretically supported for this function ( see http://man7.org/linux/man- pages/man3/adjtime.3.html ). The question for this one is whether this is a ntpdate bug (maybe just for arm?) or if ntpdate should not really be used for this job. Finally, for testing this I have used UTC+0 to avoid time zone to interfere. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1392292 Title: Clock doesn't update when switching time from manual to automatic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-system-settings/+bug/1392292/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
