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+'\" t
+.\"     Title: chronyd
+.\"    Author: [see the "AUTHORS" section]
+.\" Generator: Asciidoctor 1.5.6.1
+.\"      Date: 2018-09-19
+.\"    Manual: System Administration
+.\"    Source: chrony @CHRONY_VERSION@
+.\"  Language: English
+.\"
+.TH "CHRONYD" "8" "2018-09-19" "chrony @CHRONY_VERSION@" "System Administration"
+.ie \n(.g .ds Aq \(aq
+.el       .ds Aq '
+.ss \n[.ss] 0
+.nh
+.ad l
+.de URL
+\\$2 \(laURL: \\$1 \(ra\\$3
+..
+.if \n[.g] .mso www.tmac
+.LINKSTYLE blue R < >
+.SH "NAME"
+chronyd \- chrony daemon
+.SH "SYNOPSIS"
+.sp
+\fBchronyd\fP [\fIOPTION\fP]... [\fIDIRECTIVE\fP]...
+.SH "DESCRIPTION"
+.sp
+\fBchronyd\fP is a daemon for synchronisation of the system clock. It can
+synchronise the clock with NTP servers, reference clocks (e.g. a GPS receiver),
+and manual input using wristwatch and keyboard via \fBchronyc\fP. It can also
+operate as an NTPv4 (RFC 5905) server and peer to provide a time service to
+other computers in the network.
+.sp
+If no configuration directives are specified on the command line, \fBchronyd\fP
+will read them from a configuration file. The compiled\-in default location of
+the file is \fI@SYSCONFDIR@/chrony.conf\fP.
+.sp
+Information messages and warnings will be logged to syslog.
+.SH "OPTIONS"
+.sp
+\fB\-4\fP
+.RS 4
+With this option hostnames will be resolved only to IPv4 addresses and only
+IPv4 sockets will be created.
+.RE
+.sp
+\fB\-6\fP
+.RS 4
+With this option hostnames will be resolved only to IPv6 addresses and only
+IPv6 sockets will be created.
+.RE
+.sp
+\fB\-f\fP \fIfile\fP
+.RS 4
+This option can be used to specify an alternate location for the configuration
+file (default \fI@SYSCONFDIR@/chrony.conf\fP).
+.RE
+.sp
+\fB\-n\fP
+.RS 4
+When run in this mode, the program will not detach itself from the terminal.
+.RE
+.sp
+\fB\-d\fP
+.RS 4
+When run in this mode, the program will not detach itself from the terminal,
+and all messages will be written to the terminal instead of syslog. When
+\fBchronyd\fP was compiled with debugging support, this option can be used twice to
+print also debugging messages.
+.RE
+.sp
+\fB\-l\fP \fIfile\fP
+.RS 4
+This option specifies a file which should be used for logging instead of syslog
+or terminal.
+.RE
+.sp
+\fB\-q\fP
+.RS 4
+When run in this mode, \fBchronyd\fP will set the system clock once and exit. It
+will not detach from the terminal.
+.RE
+.sp
+\fB\-Q\fP
+.RS 4
+This option is similar to the \fB\-q\fP option, except it only prints the offset
+without making any corrections of the clock and it allows \fBchronyd\fP to be
+started without root privileges.
+.RE
+.sp
+\fB\-r\fP
+.RS 4
+This option will try to reload and then delete files containing sample
+histories for each of the servers and reference clocks being used. The
+files are expected to be in the directory specified by the
+\fBdumpdir\fP
+directive in the configuration file. This option is useful if you want to stop
+and restart \fBchronyd\fP briefly for any reason, e.g. to install a new version.
+However, it should be used only on systems where the kernel can maintain clock
+compensation whilst not under \fBchronyd\fP\(cqs control (i.e. Linux, FreeBSD, NetBSD,
+Solaris, and macOS 10.13 or later).
+.RE
+.sp
+\fB\-R\fP
+.RS 4
+When this option is used, the \fBinitstepslew\fP
+directive and the \fBmakestep\fP directive used with
+a positive limit will be ignored. This option is useful when restarting
+\fBchronyd\fP and can be used in conjunction with the \fB\-r\fP option.
+.RE
+.sp
+\fB\-s\fP
+.RS 4
+This option will set the system clock from the computer\(cqs real\-time clock (RTC)
+or to the last modification time of the file specified by the
+\fBdriftfile\fP directive. Real\-time clocks are
+supported only on Linux.
+.sp
+If used in conjunction with the \fB\-r\fP flag, \fBchronyd\fP will attempt to preserve
+the old samples after setting the system clock from the RTC. This can be used
+to allow \fBchronyd\fP to perform long term averaging of the gain or loss rate
+across system reboots, and is useful for systems with intermittent access to
+network that are shut down when not in use. For this to work well, it relies
+on \fBchronyd\fP having been able to determine accurate statistics for the
+difference between the RTC and system clock last time the computer was on.
+.sp
+If the last modification time of the drift file is later than both the current
+time and the RTC time, the system time will be set to it to restore the time
+when \fBchronyd\fP was previously stopped. This is useful on computers that have no
+RTC or the RTC is broken (e.g. it has no battery).
+.RE
+.sp
+\fB\-t\fP \fItimeout\fP
+.RS 4
+This option sets a timeout (in seconds) after which \fBchronyd\fP will exit. If the
+clock is not synchronised, it will exit with a non\-zero status. This is useful
+with the \fB\-q\fP or \fB\-Q\fP option to shorten the maximum time waiting for
+measurements, or with the \fB\-r\fP option to limit the time when \fBchronyd\fP is
+running, but still allow it to adjust the frequency of the system clock.
+.RE
+.sp
+\fB\-u\fP \fIuser\fP
+.RS 4
+This option sets the name of the system user to which \fBchronyd\fP will switch
+after start in order to drop root privileges. It overrides the
+\fBuser\fP directive (default \fI@DEFAULT_USER@\fP).
+.sp
+On Linux, \fBchronyd\fP needs to be compiled with support for the \fBlibcap\fP library.
+On macOS, FreeBSD, NetBSD and Solaris \fBchronyd\fP forks into two processes.
+The child process retains root privileges, but can only perform a very limited
+range of privileged system calls on behalf of the parent.
+.RE
+.sp
+\fB\-F\fP \fIlevel\fP
+.RS 4
+This option configures a system call filter when \fBchronyd\fP is compiled with
+support for the Linux secure computing (seccomp) facility. In level 1 the
+process is killed when a forbidden system call is made, in level \-1 the SIGSYS
+signal is thrown instead and in level 0 the filter is disabled (default 0).
+.sp
+It\(cqs recommended to enable the filter only when it\(cqs known to work on the
+version of the system where \fBchrony\fP is installed as the filter needs to allow
+also system calls made from libraries that \fBchronyd\fP is using (e.g. libc) and
+different versions or implementations of the libraries may make different
+system calls. If the filter is missing some system call, \fBchronyd\fP could be
+killed even in normal operation.
+.RE
+.sp
+\fB\-P\fP \fIpriority\fP
+.RS 4
+On Linux, this option will select the SCHED_FIFO real\-time scheduler at the
+specified priority (which must be between 0 and 100). On macOS, this option
+must have either a value of 0 (the default) to disable the thread time
+constraint policy or 1 for the policy to be enabled. Other systems do not
+support this option.
+.RE
+.sp
+\fB\-m\fP
+.RS 4
+This option will lock \fBchronyd\fP into RAM so that it will never be paged out.
+This mode is only supported on Linux.
+.RE
+.sp
+\fB\-x\fP
+.RS 4
+This option disables the control of the system clock. \fBchronyd\fP will not try to
+make any adjustments of the clock. It will assume the clock is free running and
+still track its offset and frequency relative to the estimated true time. This
+option allows \fBchronyd\fP to run without the capability to adjust or set the
+system clock (e.g. in some containers) in order to operate as an NTP server. It
+is not recommended to run \fBchronyd\fP (with or without \fB\-x\fP) when another process
+is controlling the system clock.
+.RE
+.sp
+\fB\-v\fP
+.RS 4
+With this option \fBchronyd\fP will print version number to the terminal and exit.
+.RE
+.SH "FILES"
+.sp
+\fI@SYSCONFDIR@/chrony.conf\fP
+.SH "SEE ALSO"
+.sp
+\fBchronyc(1)\fP, \fBchrony.conf(5)\fP
+.SH "BUGS"
+.sp
+For instructions on how to report bugs, please visit
+.URL "https://chrony.tuxfamily.org/" "" "."
+.SH "AUTHORS"
+.sp
+chrony was written by Richard Curnow, Miroslav Lichvar, and others.
+\ No newline at end of file