"Failed to start ntpd.service — Amazon Linux 2023 replaced it with chrony"

You moved an AMI, launch template, or Ansible playbook from Amazon Linux 2 to Amazon Linux 2023, and time-sync provisioning that used to just work now fails:

Failed to start ntpd.service: Unit ntpd.service not found.

The instance boots fine, dnf works, but whatever enabled or started ntpd.service — user-data, cloud-init, a Packer build, a config-management run — has nothing to attach to.

Why this happens

Amazon Linux 2 shipped ntp/ntpd for time synchronization. Amazon Linux 2023 doesn't install that package or unit by default — it standardizes on chrony (chronyd) instead, the same time-sync daemon most modern Linux distros have already moved to. Anything that assumes ntpd.service exists — a systemctl enable --now ntpd line baked into a golden AMI, a cloud-init runcmd, an Ansible task targeting ntp.conf — has no unit to enable on AL2023.

The fix

# Install and enable chrony (often already present on AL2023 AMIs — check first)
sudo dnf install -y chrony
sudo systemctl enable --now chronyd

# Verify it's syncing
chronyc sources
chronyc tracking

If you had custom NTP servers configured in /etc/ntp.conf, migrate the server/pool lines to /etc/chrony.conf (chrony's syntax is close enough that most entries port over as-is — just double-check any iburst/prefer flags still parse).

Fixing the automation, not just the instance

A one-time fix on a running instance doesn't help if the same user-data or Ansible role provisions the next hundred instances off a stale AL2 assumption. Grep provisioning code for the old unit name and update it once at the source:

grep -rl "ntpd.service\|ntp\.conf\|dnf install.*ntp[^d]\|yum install.*ntp[^d]" user-data/ ansible/ packer/

Replace systemctl enable --now ntpd with systemctl enable --now chronyd, and drop any dnf install ntp line — that package isn't what AL2023 uses for this.

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This is one piece of the broader Amazon Linux 2 → 2023 migration (package manager, firewall, time sync, and Python version all shift at once) — the full checklist is at eolkits.com/fix/amazon-linux-2-eol. If you want to know which instances in your account are still on AL2 before support ends, the free EOLkits scanner checks in about 30 seconds — nothing uploaded, and I maintain it.