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ntp.drift(4)
NAME
  ntp.drift - Network Time Protocol (NTP) drift file

DESCRIPTION
  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

  freq_offset
      Specifies the nominal frequency offset.  DO NOT modify this field.

  flag
      Specifies the method used to improve system clock accuracy.

      0 Specifies that xntpd runs a Phase-Locked Loop (PLL) algorithm to keep
	synchronized with other hosts.	This is the default.

      1 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.

FILES
  /etc/ntp.drift
	    Conventional name of the drift file

RELATED INFORMATION
  Commands: ntpdate(8), ntpq(8), xntpd(8), xntpdc(8)

  Files: ntp.conf(4)

  Network Administration: Services, System Administration

Index for Section 4

Alphabetical listing for N

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