NAME
hostname - Local hostname configuration fileSYNOPSIS
/etc/hostnameDESCRIPTION
The /etc/hostname file configures the name of the local system. Unless overridden as described in the next section, systemd(1) will set this hostname during boot using the sethostname(2) system call. The file should contain a single newline-terminated hostname string. Comments (lines starting with a "#") are ignored. The hostname should be composed of up to 64 7-bit ASCII lower-case alphanumeric characters or hyphens forming a valid DNS domain name. It is recommended that this name contains only a single label, i.e. without any dots. Invalid characters will be filtered out in an attempt to make the name valid, but obviously it is recommended to use a valid name and not rely on this filtering. You may use hostnamectl(1) to change the value of this file during runtime from the command line. Use systemd-firstboot(1) to initialize it on mounted (but not booted) system images.HOSTNAME SEMANTICS
systemd(1) and the associated tools will obtain the hostname in the following ways:•If the kernel commandline parameter
systemd.hostname= specifies a valid hostname, systemd(1) will
use it to set the hostname during early boot, see
kernel-command-line(7),
•Otherwise, the "static"
hostname specified by /etc/hostname as described above will be used.
•Otherwise, a transient hostname may be
set during runtime, for example based on information in a DHCP lease, see
systemd-hostnamed.service(8). Both NetworkManager[1] and
systemd-networkd.service(8) allow this. Note that
systemd-hostnamed.service(8) gives higher priority to the static
hostname, so the transient hostname will only be used if the static hostname
is not configured.
•Otherwise, a fallback hostname
configured at compilation time will be used ("localhost").
Effectively, the static hostname has higher priority than a transient hostname,
which has higher priority than the fallback hostname. Transient hostnames are
equivalent, so setting a new transient hostname causes the previous transient
hostname to be forgotten. The hostname specified on the kernel command line is
like a transient hostname, with the exception that it has higher priority when
the machine boots. Also note that those are the semantics implemented by
systemd tools, but other programs may also set the hostname.
HISTORY
The simple configuration file format of /etc/hostname originates from Debian GNU/Linux.SEE ALSO
systemd(1), sethostname(2), hostname(1), hostname(7), machine-id(5), machine-info(5), hostnamectl(1), systemd-hostnamed.service(8), systemd-firstboot(1)NOTES
- 1.
- NetworkManager
systemd 252 |