/usr/bin/chronyd --help — Chainguard OS Manuals

From chrony 4.9-r4 (os), captured 2026-11-05 by running chronyd --help (exit 0). permalink

Usage: /usr/bin/chronyd [OPTION]... [DIRECTIVE]...

Options:
  -4		Use IPv4 addresses only
  -6		Use IPv6 addresses only
  -f FILE	Specify configuration file (/etc/chrony/chrony.conf)
  -n		Don't run as daemon
  -d		Don't run as daemon and log to stderr
  -l FILE	Log to file
  -L LEVEL	Set logging threshold (0)
  -p		Print configuration and exit
  -q		Set clock and exit
  -Q		Log offset and exit
  -r		Reload dump files
  -R		Adapt configuration for restart
  -s		Set clock from RTC
  -t SECONDS	Exit after elapsed time
  -u USER	Specify user (chrony)
  -U		Don't check for root
  -F LEVEL	Set system call filter level (0)
  -P PRIORITY	Set process priority (0)
  -m		Lock memory
  -x		Don't control clock
  -N FD		Notify supervisor
  -v, --version	Print version and exit
  -h, --help	Print usage and exit

Options (23)

Option	Description	Source
`-4`	With this option hostnames will be resolved only to IPv4 addresses and only IPv4 sockets will be created.	help + man
`-6`	With this option hostnames will be resolved only to IPv6 addresses and only IPv6 sockets will be created.	help + man
`-f` FILE	This option can be used to specify an alternate location for the configuration file.	help + man
`-n`	When run in this mode, the program will not detach itself from the terminal.	help + man
`-d`	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.	help + man
`-l` FILE	This option enables writing of log messages to a file instead of syslog or the terminal.	help + man
`-L` LEVEL	This option specifies the minimum severity level of messages to be written to the log file, syslog, or terminal.	help + man
`-p`	When run in this mode, chronyd will print the configuration and exit.	help + man
`-q`	When run in this mode, chronyd will set the system clock once and exit.	help + man
`-Q`	This option is similar to the -q option, except it only prints the offset without making any corrections of the clock and disables server ports to allow chronyd to be started without root privileges,…	help + man
`-r`	This option will try to reload and then delete files containing sample histories for each of the servers and reference clocks being used.	help + man
`-R`	When this option is used, the initstepslew directive and the makestep directive used with a positive limit will be ignored.	help + man
`-s`	This option will set the system clock from the computer’s real-time clock (RTC) or to the last modification time of the file specified by the driftfile directive.	help + man
`-t` SECONDS	This option sets a timeout (in seconds) after which chronyd will exit.	help + man
`-u` USER	This option sets the name of the system user to which chronyd will switch after start in order to drop root privileges.	help + man
`-U`	This option disables a check for root privileges to allow chronyd to be started under a non-root user, assuming the process will have all capabilities (e.g. provided by the service manager) and…	help + man
`-F` LEVEL	This option configures system call filters loaded by chronyd processes if it was compiled with support for the Linux secure computing (seccomp) facility or OpenBSD pledge.	help + man
`-P` PRIORITY	On Linux, FreeBSD, NetBSD, OpenBSD, and illumos this option will select the SCHED_FIFO real-time scheduler at the specified priority (which must be between 0 and 100).	help + man
`-m`	This option will lock chronyd into RAM so that it will never be paged out.	help + man
`-x`	This option disables the control of the system clock.	help + man
`-N` FD	This option specifies a file descriptor that chronyd will write a newline to after it is fully initialised.	help + man
`-v, --version`	With this option chronyd will print version number to the terminal and exit.	help + man
`-h, --help`	With this option chronyd will print a help message to the terminal and exit.	help + man

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.