This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.
What this hour is for
How to Extend the Root Filesystem on Debian is one lab change on a Debian host you administer. Extending root is the volume you identified, then the filesystem grow command that matches ext4 or XFS.
Debian, not Ubuntu. Package names and the network file can differ. The network path on this host is: the network file this host already uses. A classic Debian host uses /etc/network/interfaces. That file is not netplan, and a netplan file is not an interfaces file. The firewall, if this change touches it, is ufw if you chose it. Do not assume firewalld..
AppArmor may be present. Do not disable it to make a package start. SELinux is not the Debian default. Do not grow a disk you have not named. Take a backup or a snapshot note first. The console stays open. Do not shrink in this hour. The filesystem size includes the space you added, and the host still answers.
The generator drafts a script. It does not log in. 192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a host because a draft included them.
The change you can finish
Apply nothing while you are writing the note. When the lab window opens, it is one change on the host named in the ticket. Read the draft, then the host, then decide.
Rollback is the file, the package version, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.
- Write the hostname and confirm you administer it.
- Save the current file, package list, or snapshot before any draft is applied.
- Generate the draft and delete every line this ticket did not name.
- Remove documentation addresses, example.com, and any secret.
- Apply one change only when the lab window is open and a console or a second session exists.
- Read the result back and compare it with the ticket.
- Stop. The next change is a different page.
Mistakes that outlive the command
Extend the Root Filesystem on Debian goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- Pasting a draft you did not read.
- The wrong hostname.
- A secret in the ticket or in git.
- Two changes in one window.
- No copy saved before the change.
- A documentation address left on a host that is leaving the lab.
- Disabling a firewall, AppArmor, or SELinux to make a check pass.
- Calling the generator output a finished production change.
- Do not grow a disk you have not named. Take a backup or a snapshot note first. The console stays open. Do not shrink in this hour.
Decisions to write down
One decision for Extend the Root Filesystem on Debian: The hostname matches. The change is only Extend the Root Filesystem. The platform habit was followed: Debian. A console or a second session exists. No secret is in the note. And the proof is: The filesystem size includes the space you added, and the host still answers.
Checks before you call it done
Confirm this before you call the change done: The hostname matches. A rollback copy exists. The draft was edited. Documentation values were removed before any apply. Management still works. And a second person can say what changed. If one of those fails, stop.
# Debian. Extend the Root Filesystem.
# apt. the network file this host already uses. A classic Debian host uses /etc/network/interfaces. That file is not netplan, and a netplan file is not an interfaces file.
# prompt-for-this is not a password.
# 192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a host because a draft included them.Before you leave the host
How to Extend the Root Filesystem on Debian ends when the hostname in the prompt matches the hostname in the ticket. If it does not, you are on the wrong host. Stop. A command that succeeded on the wrong host is not progress.
The draft stays a draft until a person has read the names in it. A generator does not log into the host and does not know which disk is empty. You delete a line that names a host, a path, or an account you did not write down.
192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a host because a draft included them.
prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save in the ticket or in git. The real secret stays in the password store.
One change is the window. If two things move and the result is wrong, you will not know which one did it. The next change waits for its own page.
If the same step fails twice, stop for the day. The failure is the result. Adding a forum command beside a half-applied change produces a host nobody can rebuild. Restore the copy you took first.
A second person reads the hostname and the change aloud. If they cannot find them in the ticket, the note is not done. Silence is not agreement. Then leave the host alone.
Tools for this guide
These tools run in the browser on this site. They do not log into your machines.
Related pillar guides
More in this cluster
The pillar for this page, and the next published pages filed with it.