On a systemd system, which command sets the static hostname persistently by writing it to /etc/hostname and applying it to the running system at once?
LPIC-1 Exam 102-500, objective 109. Networking fundamentals medium
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How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Not correct hostname -s myserver
Wrong. -s asks the hostname command to print the short name; it is a display option, not a way to set the name, and plain `hostname NAME` changes only the running kernel value until reboot.
Not correct echo myserver > /etc/hosts
Wrong, and destructive. This overwrites the static host table, removing the localhost entries. /etc/hosts maps addresses to names; it is not where the system's own hostname is stored.
Correct hostnamectl set-hostname myserver
Correct. hostnamectl writes the static hostname to /etc/hostname and updates the kernel hostname immediately, so no reboot is needed.
Not correct uname -n myserver
Wrong. uname reports system information and -n prints the current node name. It has no ability to change anything.
Why
The hostname exists in two places: the value the running kernel holds (shown by `hostname` or `uname -n`, set for this boot by `hostname NAME`) and the persistent value in /etc/hostname read at boot. hostnamectl updates both. It is good practice to also list the hostname beside the machine's address in /etc/hosts so that the name resolves even without DNS.
Where this comes from
- Cited
- LPI exam objective 109.2
- What it says
- Set and query the system hostname.
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 109 and space the ones you get wrong.
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