1TIMESYNCD.CONF(5) timesyncd.conf TIMESYNCD.CONF(5)
2
6 timesyncd.conf, timesyncd.conf.d - Network Time Synchronization
7 configuration files
8
10 /etc/systemd/timesyncd.conf
11 /etc/systemd/timesyncd.conf.d/*.conf
13 /run/systemd/timesyncd.conf.d/*.conf
15 /usr/lib/systemd/timesyncd.conf.d/*.conf
17
19 These configuration files control NTP network time synchronization. See
20 systemd.syntax(5) for a general description of the syntax.
21
23 The default configuration is defined during compilation, so a
24 configuration file is only needed when it is necessary to deviate from
25 those defaults. By default, the configuration file in /etc/systemd/
26 contains commented out entries showing the defaults as a guide to the
27 administrator. This file can be edited to create local overrides.
28 When packages need to customize the configuration, they can install
30 configuration snippets in /usr/lib/systemd/*.conf.d/ or
31 /usr/local/lib/systemd/*.conf.d/. Files in /etc/ are reserved for the
32 local administrator, who may use this logic to override the
33 configuration files installed by vendor packages. The main
34 configuration file is read before any of the configuration directories,
35 and has the lowest precedence; entries in a file in any configuration
36 directory override entries in the single configuration file. Files in
37 the *.conf.d/ configuration subdirectories are sorted by their filename
38 in lexicographic order, regardless of which of the subdirectories they
39 reside in. When multiple files specify the same option, for options
40 which accept just a single value, the entry in the file with the
41 lexicographically latest name takes precedence. For options which
42 accept a list of values, entries are collected as they occur in files
43 sorted lexicographically. It is recommended to prefix all filenames in
44 those subdirectories with a two-digit number and a dash, to simplify
45 the ordering of the files.
46 To disable a configuration file supplied by the vendor, the recommended
48 way is to place a symlink to /dev/null in the configuration directory
49 in /etc/, with the same filename as the vendor configuration file.
50
52 The following settings are configured in the "[Time]" section:
53 NTP=
55 A space-separated list of NTP server host names or IP addresses.
56 During runtime this list is combined with any per-interface NTP
57 servers acquired from systemd-networkd.service(8).
58 systemd-timesyncd will contact all configured system or
59 per-interface servers in turn until one is found that responds.
60 When the empty string is assigned, the list of NTP servers is
61 reset, and all assignments prior to this one will have no effect.
62 This setting defaults to an empty list.
63 FallbackNTP=
65 A space-separated list of NTP server host names or IP addresses to
66 be used as the fallback NTP servers. Any per-interface NTP servers
67 obtained from systemd-networkd.service(8) take precedence over this
68 setting, as do any servers set via NTP= above. This setting is
69 hence only used if no other NTP server information is known. When
70 the empty string is assigned, the list of NTP servers is reset, and
71 all assignments prior to this one will have no effect. If this
72 option is not given, a compiled-in list of NTP servers is used
73 instead.
74 RootDistanceMaxSec=
76 Maximum acceptable root distance. Takes a time value (in seconds).
77 Defaults to 5 seconds.
78 PollIntervalMinSec=, PollIntervalMaxSec=
80 The minimum and maximum poll intervals for NTP messages. Each
81 setting takes a time value (in seconds). PollIntervalMinSec= must
82 not be smaller than 16 seconds. PollIntervalMaxSec= must be larger
83 than PollIntervalMinSec=. PollIntervalMinSec= defaults to 32
84 seconds, and PollIntervalMaxSec= defaults to 2048 seconds.
85
87 systemd(1), systemd-timesyncd.service(8), systemd-networkd.service(8)
88systemd 243 TIMESYNCD.CONF(5)