Unruh wrote: > "Richard B. Gilbert" <[EMAIL PROTECTED]> writes: > > >> There are other tools than NTPD. One called "chrony" MAY meet your >> needs, or may not. NTPD is very good at working over the Internet with >> its unpredictable queuing delays. Chrony, as I understand it, is not so >> good at working over the internet. > > No idea where you get this from. chrony works over the internet at least as > well as does ntpd. Its philosophy of dealing with different delays is > different than ntp's( although it can be set up to be virtually identical) > > >> If you can't keep your machines up 24x7, chrony MAY be a better tool. >> It's possible that you will need something else entirely. > > Possibly true. > > >> You may find that a hardware reference clock; e.g. a GPS timing >> receiver, will help. With a GPS timing receiver, you will not be >> dependent on the internet for time sources. NTPD will still need about >> thirty minutes to gain really tight synchronization. Once gained, >> synchronization should be stable as long as the machine is up. > > Actually it is much worse than that. On my system, on bootup the clock > frequency can very by up to about 50PPM due to a Linux bug. In general it > takes ntp about 10 hours to regain tight synchronisation. (In that case it > is microsecond since it is synching to a GPS, but it is also on poll level > 4 so it has lots of data and should converge faster than some other system > on poll level 6-10). David Mills has always insisted that ntpd is designed > for stable long time operation, and rapidity of response is a distant 49th > or so in priority. >
My Solaris 8 SPARC system seems to be able to synch with the GPS receiver in about 30 minutes. I may reboot that system once a year unless we have a power outrage that lasts longer than the UPS battery! Absent something like a power failure there's no real reason to reboot it at all. _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
