For example, I will update phpBB version 3.3.3 to 3.3.4.
We will definitely make a backup copy of the forum:
sudo tar -cvjf backup_forum_files.tar.bz2 /var/www/ixnfo_com_forum/
mysqldump -u root ixnfo_com_forum | gzip -c > ixnfo_com_forum.sql.gz
Download the archive with update files from the official website:
wget https://download.phpbb.com/pub/release/3.3/3.3.4/phpBB-3.3.3_to_3.3.4.zip
Unpack the downloaded archive and move the docs, install, vendor directories to the root directory of the forum, after moving the install directory, the forum will automatically switch off to maintenance mode. If the directories were moved through the terminal, and not through cPanel, etc., then the owner and group from which the web server is running must be set on them, in Ubuntu this is usually www-data:
unzip phpBB-3.3.3_to_3.3.4.zip
sudo chown -R www-data:www-data /var/www/ixnfo_com_forum/
Let’s open the update script in the browser, for example https://ixnfo.com/forum/install/app.php and follow the instructions, at the first step, the files are updated, it may take longer than usual if many third-party plugins are used or changes are made to standard files, for example I previously made changes to the standard theme files.
The second step was to update the database, which was successful. Then I deleted the install directory, and that was the end of the update process.
See my other articles on phpBB