ntp.drift - Network Time Protocol (NTP) drift file
When the NTP daemon (xntpd) is first started, it computes
the error in the intrinsic frequency of the clock on the
computer it is running on. This process usually takes
about a day or two after the daemon is started to compute
a good estimate of this (and it needs a good estimate to
synchronize closely to its server). Once the initial
value is computed, it will change only by relatively small
amounts during the course of continued operation.
The driftfile declaration should always be included in the
ntp.conf file. This provides xntpd with complete path
name to a file in which it can store the current value of
the frequency error. That way, if the daemon is stopped
and restarted, it can reinitialize itself to the previous
estimate without spending time recomputing the frequency
estimate.
The ntp.drift file contains one line with the following
format: freq_offset flag Specifies the nominal frequency
offset. DO NOT modify this field. Specifies the method
used to improve system clock accuracy. Specifies that
xntpd runs a Phase-Locked Loop (PLL) algorithm to keep
synchronized with other hosts. This is the default.
Specifies the use of the PLL algorithm in the kernel.
This requires the NTP_TIME kernel option. After the
option is configured in the kernel, edit the ntp.drift
file and change the flag value to 1.
See System Administration for information on the
NTP_TIME kernel option.
Conventional name of the drift file
Commands: ntpdate(8), ntpq(8), xntpd(8), xntpdc(8)
Files: ntp.conf(4)
Network Administration: Services, System Administration
delim off
ntp.drift(4)
[ Back ] | 