A few days ago Nextcloud was officially announced and the Nextcloud team crafted a new release rather quickly.
The following steps were required to migrate from ownCloud 8.2.5 to Nextcloud 9.0.50:
- Create a backup of the current ownCloud installation.
- Install Nextcloud by following this migration guide.
- Perform the actual upgrade for all apps:
$ php occ upgrade --no-app-disable. - For each third party app: disable it in the WebUI, reload, enable it in the WebUI.
- Recover missing files:
$ php occ files:scan --all. - Check if the calendar/contacts migration worked as expected.
- Update the Nginx configuration.
- Remove the old ownCloud installation.
- For each mobile phone: replace the ownCloud app with the Nextcloud app.
Have fun.