CHRONYD(8) System Administration CHRONYD(8) (NAME) chronyd - chrony (SYNOPSIS) chronyd []... []... (DESCRIPTION) chronyd . NTP ( GPS) chronyc . (peer) NTPv4 ( RFC 5905) . chronyd . /etc/chrony.conf . syslog . (OPTIONS) -4 IPv4 IPv4 . -6 IPv6 IPv6 . -f . /etc/chrony.conf . -n ( ). -d syslog . chronyd . -l syslog . -L syslog . : -1 ( ) 0 () 1 () 2 ( ) 3 ( ). 0 . -p chronyd . . () include confdir . -q chronyd . . -Q -q (offset) chronyd (root) ( refclock hwtimestamp rtcfile ). -r . dumpdir . chronyd . chronyd ( FreeBSD NetBSD illumos macOS 10.13 ). -R initstepslew makestep . chronyd -r . -s (RTC) driftfile . (RTC) . -r chronyd RTC . chronyd . chronyd RTC . drift RTC chronyd . RTC RTC ( ) . -t ( ) chronyd . . -q -Q -r chronyd . -u chronyd (root) . user . chrony . chronyd libcap . macOS FreeBSD NetBSD illumos chronyd (fork) . . -U chronyd (capabilities ) . . chronyd . -F chronyd (seccomp) . : 0 1 2. 0 . 1 2 chronyd (kill ). SIGKILL SIGSYS . 0 . 1 chronyd . . chrony . chronyd ( libc) . chronyd . 2 ( fork exec) . (false positive) chronyd . mailonchange . -P FreeBSD NetBSD illumos SCHED_FIFO ( 0 100 ) . macOS 0 ( ) 1 ( ) . . 0 . -m chronyd (/swap) . FreeBSD NetBSD illumos . -x . chronyd . . chronyd ( ) NTP . -v, --version chronyd . -h, --help chronyd . (ENVIRONMENT VARIABLES) LISTEN_FDS systemd (file descriptors) chronyd . (bind) . (zero-downtime) . LISTEN_FDS . NOTIFY_SOCKET systemd notify . chronyd ( chronyc) -s initstepslew . forking (PID file) . (fork) chronyd -n -d . (FILES) /etc/chrony.conf (SEE ALSO) chronyc(1), chrony.conf(5) (BUGS) : . (AUTHORS) chrony (Richard Curnow) (Miroslav Lichvar) . chrony 4.8 2026-04-30 CHRONYD(8)