On Thu, May 31, 2018 at 07:07:57PM +0530, प्रदीप कुमार भट्ट wrote: > I am facing issues w.r.t the time source selection. I have 1 PTP source and > 3 NTP sources. Whenever all 4 sources are present and working, the local > clock gets synchronized with the PTP master but as soon as I make the PTP > master offline, the timemaster service does not switch to any of NTP > sources and always indicates that it is synced to PTP, which is false . I > have tested this for continuous 24 hours of operation. However , when I > restart the timemaster service, it gets synchronized with the best NTP > server. So every time, I have to restart the timemaster service when the > PTP master fails. > Looking forward for a solution and possible configuration change if > required.
timemaster doesn't actually select between sources. It just configures and starts an NTP daemon to use them. Is it chrony? When a time source stops working and others are available, the switch shouldn't happen immediately. It depends on how good are the sources and how stable is the clock. If the PTP source was accurate to 1 microsecond and the NTP sources only to 100 milliseconds, it would normally be better to keep the clock running freely for many hours before switching in order to minimize the error of the clock. So, if you force the reselection by restarting the service, the accuracy may actually be worse. However, there were some changes related to the reselection in chrony recently. If you think it's taking too long, you might want to try upgrading to 3.3. -- Miroslav Lichvar ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
