Database #

owncloud.online runs on MariaDB/MySQL, PostgreSQL, or SQLite. For production, MariaDB is the tested standard. SQLite is only suitable for local tests and breaks down under concurrent access.

Recommended settings (MariaDB/MySQL) #

The database must use utf8mb4. Otherwise file names with emojis or rare characters fail:

CREATE DATABASE owncloud_online
  CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;

config.php needs:

'dbtype' => 'mysql',
'mysql.utf8mb4' => true,

To check whether an existing instance has already been converted, run the following command. The expected output is true:

sudo -u www-data php8.4 /var/www/owncloud.online/occ config:system:get mysql.utf8mb4

db:convert-mysql-charset does the conversion. It first checks whether the database server supports utf8mb4, then sets mysql.utf8mb4 in config.php and converts all tables. Make a backup first and turn on maintenance mode:

sudo -u www-data php8.4 /var/www/owncloud.online/occ maintenance:mode --on
sudo -u www-data php8.4 /var/www/owncloud.online/occ db:convert-mysql-charset
sudo -u www-data php8.4 /var/www/owncloud.online/occ maintenance:mode --off

Switching from SQLite to MariaDB #

This version has no in-place conversion. The former db:convert-type command has been removed (changelog: "This experimental command is untested and unsupported and therefore removed."). Plan for MariaDB when you install.

For an existing SQLite instance, the only way is a fresh installation with MariaDB and a new scan of the files. Everything that exists only in the database is lost, such as shares, comments, tags, and app settings. Moving to another server describes the procedure and the full list.

Maintenance #

The server creates indexes and columns through migrations. There is no separate command for adding missing indexes.

# show the migration state ("New Migrations" should be 0)
sudo -u www-data php8.4 /var/www/owncloud.online/occ migrations:status core

# run pending migrations up to the latest version
sudo -u www-data php8.4 /var/www/owncloud.online/occ migrations:migrate core

# run a single migration
sudo -u www-data php8.4 /var/www/owncloud.online/occ migrations:execute core <version>

After moving to MariaDB 10.6 or later, db:restore-default-row-format converts all tables whose row format differs from the server default (such as the deprecated COMPRESSED) to the default format:

sudo -u www-data php8.4 /var/www/owncloud.online/occ db:restore-default-row-format

Backup and restore #

# backup
mkdir -p /var/backups/owncloud.online
mysqldump --single-transaction -u root -p owncloud_online > /var/backups/owncloud.online/db-$(date +%F).sql

# restore (put the instance into maintenance mode first)
mysql -u root -p owncloud_online < /var/backups/owncloud.online/db-YYYY-MM-DD.sql

Always back up the database and the data directory at the same point in time. Otherwise metadata points to files that do not exist (anymore). Backups and updates describes the full procedure.

Common problems #