From b750101eb236130cf056c675997decbac904cc49 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 17:35:18 +0200 Subject: Adding upstream version 252.22. Signed-off-by: Daniel Baumann --- man/systemd-timesyncd.service.xml | 127 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 man/systemd-timesyncd.service.xml (limited to 'man/systemd-timesyncd.service.xml') diff --git a/man/systemd-timesyncd.service.xml b/man/systemd-timesyncd.service.xml new file mode 100644 index 0000000..45fb6b7 --- /dev/null +++ b/man/systemd-timesyncd.service.xml @@ -0,0 +1,127 @@ + + + + + + + + systemd-timesyncd.service + systemd + + + + systemd-timesyncd.service + 8 + + + + systemd-timesyncd.service + systemd-timesyncd + Network Time Synchronization + + + + systemd-timesyncd.service + /usr/lib/systemd/systemd-timesyncd + + + + Description + + systemd-timesyncd is a system service that may be used to synchronize the + local system clock with a remote Network Time Protocol (NTP) server. It also saves the local time to disk + every time the clock has been synchronized and uses this to possibly advance the system realtime clock on + subsequent reboots to ensure it (roughly) monotonically advances even if the system lacks a + battery-buffered RTC chip. + + The systemd-timesyncd service implements SNTP only. This minimalistic service + will step the system clock for large offsets or slowly adjust it for smaller deltas. Complex use cases + that require full NTP support (and where SNTP is not sufficient) are not covered by + systemd-timesyncd. + + The NTP servers contacted are determined from the global settings in + timesyncd.conf5, the + per-link static settings in .network files, and the per-link dynamic settings + received over DHCP. See + systemd.network5 for + further details. + + timedatectl1's + set-ntp command may be used to enable and start, or disable and stop this + service. + + timedatectl1's + timesync-status or show-timesync command can be used to show the + current status of this service. + + systemd-timesyncd initialization delays the start of units that are ordered + after time-set.target (see + systemd.special7 for + details) until the local time has been updated from /var/lib/systemd/timesync/clock + (see below) in order to make it roughly monotonic. It does not delay other units until synchronization + with an accurate reference time sources has been reached. Use + systemd-time-wait-sync.service8 + to achieve that, which will delay start of units that are ordered after + time-sync.target until synchronization to an accurate reference clock is + reached. + + + + Files + + + + /var/lib/systemd/timesync/clock + + + The modification time ("mtime") of this file is updated on each successful NTP + synchronization or after each SaveIntervalSec= time interval, as specified in + timesyncd.conf5. + + When initializing, the local clock is advanced to the modification time of this file (if the + file timestamp is in the past this adjustment is not made). If the file does not exist yet, the + clock is instead advanced to the modification time of /usr/lib/clock-epoch – + if it exists – or to a time derived from the source tree at build time. This mechanism is used to + ensure that the system clock remains somewhat reasonably initialized and roughly monotonic across + reboots, in case no battery-buffered local RTC is available. + + + + + /usr/lib/clock-epoch + + The modification time ("mtime") of this file is used for advancing the system clock + in case /var/lib/systemd/timesync/clock does not exist yet, see + above. + + + + /run/systemd/timesync/synchronized + + + A file that is touched on each successful synchronization, to assist + systemd-time-wait-sync and other applications to detecting synchronization + with accurate reference clocks. + + + + + + + + See Also + + systemd1, + timesyncd.conf5, + systemd.network5, + systemd-networkd.service8, + systemd-time-wait-sync.service8, + systemd.special7, + timedatectl1, + localtime5, + hwclock8 + + + + -- cgit v1.2.3