Time Sync with chrony — MyAdminDesk

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

The generator drafts a client config. A server also needs an allow line and a local stratum if it serves other hosts. The drift calculator uses numbers you type. Neither tool connects. 192.0.2.123 is documentation.

The peer is a host you operate or a public source you already chose. Do not point the host at a name you cannot say. Do not restart chrony during the reading.

192.0.2.10/24 and example.com are documentation. They stay in the note.

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.

Name the peer.
Replace the documentation address.
Say whether this host serves others.
Do not restart.
Stop.

Mistakes that outlive the command

Time Sync with chrony goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.

A peer you cannot name.
Time served to the internet by accident.
Two time services left running.
A restart during the reading.

Decisions to write down

One decision for Time Sync with chrony: One peer you can name. Serving others is yes or no. Documentation addresses are gone. And nothing was restarted.

Checks before you call it done

Confirm this before you call the change done: The peer is written. Serving others is written. Nothing was restarted. The address is not 192.0.2.123 unless that is truly your lab. And one time service. If one of those fails, stop.

# One peer you can name.
# 192.0.2.123 is documentation.
# Do not restart during the reading.

Before you leave the host

Time Sync with chrony 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.

This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a host you do not administer. You do not disable a firewall, AppArmor, or SELinux to make a check pass.

Tools for this guide

These tools run in the browser on this site. They do not log into your machines.

Linux Logging Guide

More in this cluster

The pillar for this page, and the next published pages filed with it.

Companion: Network: NTP Explained and How to Check Time Sync.