Behind the scenes of the "move data disk" feature

FloatingBoater · December 14, 2024, 6:35pm

My understanding is “Move Data Disk” WONT copy over a boot loader, but with the prospect of upgrades from CM4 to CM5 modules, a new install of HAOS 14 will ignore eMMC and install both OS and data on SSD to make upgrades easier (e.g. just move the SSD over).

The change in HA OS 14:

github.com/home-assistant/operating-system

Always use NVMe datadisk on Yellow if it's present on first boot

home-assistant:dev ← home-assistant:yellow-always-prefer-nvme-datadisk

opened 01:59PM - 21 Nov 24 UTC

sairon

+51 -12

If HAOS on Yellow is booted for the first time with NVMe data disk present, it s…hould be preferred over the empty eMMC data partition. This will ease reinstall of the system and migration from CM4 to CM5. All other data disks (e.g. if a USB drive is used for them) are still treated as before, requiring manual adoption using the Supervisor repair. ## Summary by CodeRabbit - **New Features** - Improved handling of data partitions based on system configuration, allowing for more intelligent management. - Introduced conditional logic for distinguishing between internal eMMC and NVMe data partitions based on the `VARIANT_ID`. - **Bug Fixes** - Enhanced functionality to ensure only one type of internal data partition is active at a time. - **Refactor** - Restructured the script for better readability and maintainability by encapsulating logic into a new function.

My Yellow has the OS images on eMMC, and user data (move data disk) on the NVMe SSD. This suggests I’ll need to backup, swap CM4 → CM5, reinstall a new HAOS to the SSD, then restore (means you can save £10 on a CM5 Lite with no eMMC).

And don’t use the CM4 bolts, and apparently the USB-2 ports can’t be used on a Yellow for a CM5, so you need to install via the USB-C serial console or perhaps using a NVMe carrier on another machine.