On Sat, Aug 27, 2011 at 9:49 AM, C BlacK <rb...@non.net> wrote: > I read somewhere that it takes an ntpd 24 hours to truly sync up to a > stratum 2 master. > > Use some logic. Assume you want to set a mechanical clock's speed by moving the "slow/fast" lever and you can see the time only to the nearest second by eye. If you want the clock to loose/gain one second per day then it will take you one day (at best) to adjust the time as it would take that long to detect an error. It you want to adjust the rate such that it only gains one second per month it would take a month before you'd know if you got it right. You have to remember that NTP works be adjusting the rate, faster or slower and tried hard to never "jump" the time. The only why for anyone to know if the rate is right is to wait, greater accuracy requires longer a wait.
NTP works kind of like this. Small errors take a long time to detect and smaller errors take even longer to detect. So up to a point NTP's error gets smaller the longer you wait. The details depend on your Internet connection and the distance to the server(s). For most people a "few" hours gets you "close" and you are almost as good as you will be after a half day. After 24 hours improvement is unlikely. So the conservative answer is "24 hours" but for most practical purposes you are "good enough for file system time stamps and the like" after 1 or 2 hours. -- Chris Albertson Redondo Beach, California _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
