hostnamectl command in Linux: host name and machine info, examples

Q: sudo hangs for a moment after changing the name

The new name doesn't resolve locally. Add it to /etc/hosts (a line 127.0.1.1 name). Check with getent hosts $(hostname) (see dns-resolv).

Q: hostname -f doesn't return an FQDN

There's no domain-qualified record in /etc/hosts/DNS. Add 127.0.1.1 host.domain host — order matters (FQDN first).

Overview

hostnamectl (systemd) shows and changes the host name and machine info (OS, kernel, virtualization, machine-id, architecture).

bash

hostnamectl                       # name, OS, kernel, virtualization, machine-id
hostname                          # just the current name (short command)
hostname -f                       # FQDN (full name via DNS/hosts)
hostname -I                       # all IP addresses of the host

Options

6

/

Without a subcommand, hostnamectl prints the static facts: name, OS, kernel, virtualization, machine-id. With set-hostname it changes the name — by default it sets static and pretty together unless you name --static/--transient/--pretty explicitly. -H runs the operation on a remote machine over SSH, without an interactive login to it.

Option	What it does	Example
`--static`	Show only the static name (from /etc/hostname).	`hostnamectl --static`
`--transient`	Show or set the transient name (from DHCP/mDNS, until reboot).	`hostnamectl set-hostname web01 --transient`
`--pretty`	Show or set the pretty name for the UI — spaces and UTF-8 allowed.	`hostnamectl set-hostname "Веб 01" --pretty`
`--json` short\|pretty\|off	Print the machine info as JSON.	`hostnamectl --json=pretty`
`-H` `--host` host	Perform the operation on a remote machine over SSH.	`hostnamectl -H user@host`
`--no-ask-password`	Do not prompt for a password interactively (for scripts).	`hostnamectl --no-ask-password set-hostname web01`

Nothing found. Try a shorter query.

Recipes

1

Three kinds of name

systemd distinguishes three host names:

Kind	Where	Command
static	`/etc/hostname`, survives reboot	`set-hostname web01`
transient	temporary (from DHCP/mDNS), until reboot	`set-hostname --transient`
pretty	"nice" name for the UI (UTF-8, spaces)	`set-hostname "Web 01" --pretty`

bash

sudo hostnamectl set-hostname web01            # static (writes /etc/hostname)
sudo hostnamectl set-hostname "Web 01" --pretty
hostnamectl --static                            # show one specific kind
sudo hostnamectl set-location "Rack 5, DC1"     # extra metadata
sudo hostnamectl set-chassis vm                 # type (vm/server/container)

After changing the name, update /etc/hosts so sudo and local lookups don't stall on resolution:

127.0.1.1   web01.example.com web01

Troubleshooting

4

sudo hangs for a moment after changing the name

The new name doesn't resolve locally. Add it to /etc/hosts (a line 127.0.1.1 name). Check with getent hosts $(hostname) (see dns-resolv).

The name "reverted" after a reboot

cloud-init or DHCP is resetting it. Disable it in cloud-init (preserve_hostname: true in /etc/cloud/cloud.cfg) or at the DHCP source.

`hostname -f` doesn't return an FQDN

There's no domain-qualified record in /etc/hosts/DNS. Add 127.0.1.1 host.domain host — order matters (FQDN first).

Same machine-id on cloned VMs

When cloning an image, machine-id must be unique, or DHCP leases and journals get confused. Reset it:

bash

sudo truncate -s0 /etc/machine-id && sudo systemd-machine-id-setup
sudo rm -f /var/lib/dbus/machine-id && sudo dbus-uuidgen --ensure

hostnamectl — host name and machine info

Cheat sheet

Overview

Options

Recipes

Three kinds of name

Troubleshooting

sudo hangs for a moment after changing the name

The name "reverted" after a reboot

`hostname -f` doesn't return an FQDN

Same machine-id on cloned VMs

See also