These instructions are based on the assumption that you have a working ownCloud (version 9.1.1) instance. To make the migration process easier I decided not to rename any existing ownCloud folders.
Some of the steps I document may not be necessary for a successful migration but they are the exact steps I used and they worked.
My server environment is as follows:
Operating System: Debian 8.6 (jessie) ownCloud version: 9.1.1 Webserver: Apache 2.4.10 ownCloud install location: /var/www/owncloud ownCloud backup location: /opt/owncloud-install
1. Download Nextcloud server version 10.0.2
2. Stop your webserver
3. Backup (move) your config.php file and your data folder
4. Delete your ownCloud folder
5. Extract Nextcloud 10.0.2 (please note that the tar ball doesn’t include a data folder or a config.php file)
6. You now have a folder named nextcloud, I’m going to rename this folder to owncloud
7. Move the config.php file and your data folder which you backed up in Step 3
8. Set the correct ownership for your Nextcloud instance (the files in the tar ball are owned by nobody)
9. Start your webserver
10. Complete the migration/upgrade to Nextcloud 10.0.2
If you use the ownCloud desktop client to sync files between your ownCloud instance and your computer (mobile device) the good news is that there is no need to install the Nextcloud desktop client. Your existing ownCloud desktop client should keep working as normal after migrating to Nextcloud.
Learn more about Nextcloud