Update from Kodi 17 to 18

Quote from the_Agent

The Last thing I want is to destroy my database.

You can always start by making a full backup of your Kodi database.

Tools like PHPMyAdmin or MySQL Workbench can do that.

Database-wise you will need to keep all Kodi clients on the same level, otherwise you will get differences in the old and new databases.

You can indeed update the Win7 machine first, and have it upgrade the database for Kodi 18.

Kodi will not delete the old database,it will remain on the database server / NAS. You can delete manually at your heart's desire when the full upgrade of all Kodi clients has been done.

Once that is done correctly, you can upgrade the LibreELEC devices to the latest Alpha/Beta (whatever is available). As there will be no more database changes, the LibreELEC will also connect to the new database.

Depending on the rest of the configuration of each Kodi client, it's up to you to pinpoint the time of update.

Normally the LibreELEC update from stable release to stable release will be done automatically (provided your update settings are default) once LibreELEC 9.0.0 is available. Upgrading sooner, from a stable release to a Alpha/Beta release, will have to be done manually.