Preparation Modes

The Mirror Manager supports two operator-facing preparation modes.

Full OS Upgrade + Phase 2

Use this when the DP is still on Ubuntu 16.04 and must reach Ubuntu 24.04 before the final DP bringup. The OS path is:

16.04 Xenial
  → 18.04 Bionic
  → 20.04 Focal
  → 22.04 Jammy
  → 24.04 Noble

After Noble is reached, Phase 2 brings the DP to 6.6.0. In this mode the Mirror Server prepares both:

the selective Ubuntu OS Core tree from Cloudflare R2
the DP 6.6.0 Phase 2 bundle from ACPS

Phase 2 Only

Use this for supported DPs that are already on Ubuntu 24.04 but still require DP 6.6.0 bringup. This mode skips R2 and OS-hop mirror preparation and prepares only the Phase 2 artifacts.

Decision table

Starting state	Mode	Final state
DP 6.2.x / 6.3.x / 6.4.x on Ubuntu 16.04	Full OS Upgrade + Phase 2	Ubuntu 24.04 + DP 6.6.0
DP 6.5.0 on Ubuntu 16.04	Full OS Upgrade + Phase 2	Ubuntu 24.04 + DP 6.6.0
Supported DP 6.2–6.5 on Ubuntu 24.04	Phase 2 Only	DP 6.6.0
Healthy DP 6.6.0 on Ubuntu 24.04	Normally no upgrade	No change

The Phase 2 target is fixed at 6.6.0 in the current application. Do not use the older 6.5.0 bringup instructions from historical runbooks for the active Mirror Manager workflow.