1HOSTNAME(5) hostname HOSTNAME(5)
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6 hostname - Local hostname configuration file
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9 /etc/hostname
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12 The /etc/hostname file configures the name of the local system. Unless
13 overridden as described in the next section, systemd(1) will set this
14 hostname during boot using the sethostname(2) system call.
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16 The file should contain a single newline-terminated hostname string.
17 Comments (lines starting with a "#") are ignored. The hostname should
18 be composed of up to 64 7-bit ASCII lower-case alphanumeric characters
19 or hyphens forming a valid DNS domain name. It is recommended that this
20 name contains only a single label, i.e. without any dots. Invalid
21 characters will be filtered out in an attempt to make the name valid,
22 but obviously it is recommended to use a valid name and not rely on
23 this filtering.
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25 You may use hostnamectl(1) to change the value of this file during
26 runtime from the command line. Use systemd-firstboot(1) to initialize
27 it on mounted (but not booted) system images.
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30 systemd(1) and the associated tools will obtain the hostname in the
31 following ways:
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33 • If the kernel commandline parameter systemd.hostname= specifies a
34 valid hostname, systemd(1) will use it to set the hostname during
35 early boot, see kernel-command-line(7),
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37 • Otherwise, the "static" hostname specified by /etc/hostname as
38 described above will be used.
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40 • Otherwise, a transient hostname may be set during runtime, for
41 example based on information in a DHCP lease, see systemd-
42 hostnamed.service(8). Both NetworkManager[1] and systemd-
43 networkd.service(8) allow this. Note that systemd-
44 hostnamed.service(8) gives higher priority to the static hostname,
45 so the transient hostname will only be used if the static hostname
46 is not configured.
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48 • Otherwise, a fallback hostname configured at compilation time will
49 be used ("fedora").
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51 Effectively, the static hostname has higher priority than a transient
52 hostname, which has higher priority than the fallback hostname.
53 Transient hostnames are equivalent, so setting a new transient hostname
54 causes the previous transient hostname to be forgotten. The hostname
55 specified on the kernel command line is like a transient hostname, with
56 the exception that it has higher priority when the machine boots. Also
57 note that those are the semantics implemented by systemd tools, but
58 other programs may also set the hostname.
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61 The simple configuration file format of /etc/hostname originates from
62 Debian GNU/Linux.
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65 systemd(1), sethostname(2), hostname(1), hostname(7), machine-id(5),
66 machine-info(5), hostnamectl(1), systemd-hostnamed.service(8), systemd-
67 firstboot(1)
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70 1. NetworkManager
71 https://developer.gnome.org/NetworkManager/stable/
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75systemd 250 HOSTNAME(5)