Rob van der Putten <[email protected]> writes: >Hi there
>One of my Debian Lenny boxes more then halved it's 'frequency' after a >software update (among others, kernel and ntpd). It used to be 43 ppm >and is now below 17 ppm and still dropping. >Is this normal? Linux seme to be having a real real problem with its time calibration routines. It's drift rate jumps on reboot by up to 50PPM from one reboot to the next. This makes the ntp.drift file totall useless ( in fact worse than useless). Because ntp has such an attrociously slow routine for finding the clock frequency (an ultrasimple Markovian second order feedback loop) it takes forever to settle down to the new drift rate ( of the order of 10 hours if you are getting time off a PPS-- the half life is about 1 hour on poll interval 4). You are better off just erasing the ntp.drift file each time you restart Linux these days before starting up ntp. Alternatively use chrony which takes 15 min or less to settle down to the correct phase and drift rate. _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
