Provided by: chrony_1.21-2_i386 bug


       chronyd - chrony background daemon


       chronyd [OPTIONS]


       chrony  is  a pair of programs for maintaining the accuracy of computer
       clocks. chronyd is a background daemon program that can be  started  at
       boot time.

       chronyd is a daemon which runs in background on the system.  It obtains
       measurements (e.g. via the network) of the system’s offset relative  to
       other  systems,  and adjusts the system time accordingly.  For isolated
       systems, the user can periodically  enter  the  correct  time  by  hand
       (using  chronyc).  In either case, chronyd determines the rate at which
       the computer gains or loses time, and compensates for this.


       chronyd  is  usually  started  at  boot-time  and  requires   superuser

       If    chronyd    has   been   installed   to   its   default   location
       /usr/local/sbin/chronyd, starting it is simply a matter of entering the


       Information messages and warnings will be logged to syslog.


       A summary of the options supported by chronyd is included below.

       -d     When  run  in this mode, the program will not detach itself from
              the terminal, and all messages will  be  sent  to  the  terminal
              instead of to syslog.

       -f conf-file
              This option can be used to specify an alternate location for the
              configuration file (default /etc/chrony/chrony.conf).

       -r     This option will reload sample histories for each of the servers
              being  used.   These  histories  are  created  by using the dump
              command in chronyc, or by setting the  dumponexit  directive  in
              the  configuration  file.   This option is useful if you want to
              stop and restart chronyd briefly for any reason, e.g. to install
              a  new  version.   However, it only makes sense on systems where
              the kernel can maintain  clock  compensation  whilst  not  under
              chronyd’s  control.   The only version where this happens so far
              is Linux.  On systems where this is not the case,  e.g.  Solaris
              and SunOS the option should not be used.

       -s     This  option will set the system clock from the computer’s real-
              time clock.  This is analogous to supplying the -s flag  to  the
              /sbin/clock program during the Linux boot sequence.

              Support  for  real-time  clocks  is  limited  at  present  - the
              criteria are described in the section on the  rtcfile  directive
              in the documentation supplied with the distribution.

              If  chronyd cannot support the real time clock on your computer,
              this option cannot be used and a warning message will be  logged
              to the syslog.

              If used in conjunction with the -r flag, chronyd will attempt to
              preserve the old samples after setting the system clock from the
              real  time  clock.  This can be used to allow chronyd to perform
              long term averaging of the  gain  or  loss  rate  across  system
              reboots,  and  is  useful for dial-up systems that are shut down
              when not in use.  For this to work well, it  relies  on  chronyd
              having  been  able  to  determine  accurate  statistics  for the
              difference between the real time clock  and  system  clock  last
              time the computer was on.

       -v     This  option  displays  chronyd’s version number to the terminal
              and exits




       Version 1.17


       To   report   bugs,   please   contact   the   author   and/or    visit


       chronyd  is documented in detail in the documentation supplied with the
       distribution (chrony.txt and chrony.texi) and is  also  available  from

       chrony(1), chronyc(1), chrony.conf(5), clock(8), xntpd(8), ntpd(8)


       Richard Curnow <>

       This man-page was written by Jan Schaumann <> as
       part   of   "The   Missing   Man   Pages    Project".     Please    see for details.