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/. The main configuration file is read
32 before any of the configuration directories, and has the lowest
33 precedence; entries in a file in any configuration directory override
34 entries in the single configuration file. Files in the *.conf.d/
35 configuration subdirectories are sorted by their filename in
36 lexicographic order, regardless of in which of the subdirectories they
37 reside. When multiple files specify the same option, for options which
38 accept just a single value, the entry in the file with the
39 lexicographically latest name takes precedence. For options which
40 accept a list of values, entries are collected as they occur in files
41 sorted lexicographically.
42 Files in /etc/ are reserved for the local administrator, who may use
44 this logic to override the configuration files installed by vendor
45 packages. It is recommended to prefix all filenames in those
46 subdirectories with a two-digit number and a dash, to simplify the
47 ordering of the files.
48 To disable a configuration file supplied by the vendor, the recommended
50 way is to place a symlink to /dev/null in the configuration directory
51 in /etc/, with the same filename as the vendor configuration file.
52
54 The following settings are configured in the "[Time]" section:
55 NTP=
57 A space-separated list of NTP server host names or IP addresses.
58 During runtime this list is combined with any per-interface NTP
59 servers acquired from systemd-networkd.service(8).
60 systemd-timesyncd will contact all configured system or
61 per-interface servers in turn until one is found that responds.
62 When the empty string is assigned, the list of NTP servers is
63 reset, and all assignments prior to this one will have no effect.
64 This setting defaults to an empty list.
65 FallbackNTP=
67 A space-separated list of NTP server host names or IP addresses to
68 be used as the fallback NTP servers. Any per-interface NTP servers
69 obtained from systemd-networkd.service(8) take precedence over this
70 setting, as do any servers set via NTP= above. This setting is
71 hence only used if no other NTP server information is known. When
72 the empty string is assigned, the list of NTP servers is reset, and
73 all assignments prior to this one will have no effect. If this
74 option is not given, a compiled-in list of NTP servers is used
75 instead.
76 RootDistanceMaxSec=
78 Maximum acceptable root distance. Takes a time value (in seconds).
79 Defaults to 5 seconds.
80 PollIntervalMinSec=, PollIntervalMaxSec=
82 The minimum and maximum poll intervals for NTP messages. Each
83 setting takes a time value (in seconds). PollIntervalMinSec= must
84 not be smaller than 16 seconds. PollIntervalMaxSec= must be larger
85 than PollIntervalMinSec=. PollIntervalMinSec= defaults to 32
86 seconds, and PollIntervalMaxSec= defaults to 2048 seconds.
87
89 systemd(1), systemd-timesyncd.service(8), systemd-networkd.service(8)
90systemd 245 TIMESYNCD.CONF(5)