Hi! Here is the situation after 'apt full-upgrade -y':
$ dpkg -l | grep -iE 'maria|mysql|galera' || true # List installed ii default-mysql-client 1.1.0 all MySQL database client binaries (metapackage) ii default-mysql-client-core 1.1.0 all MySQL database core client binaries (metapackage) ii default-mysql-server 1.1.0 all MySQL database server binaries and system database setup (metapackage) ii default-mysql-server-core 1.1.0 all MySQL database server binaries (metapackage) ii galera-4 26.4.11-1+b2 amd64 Replication framework for transactional applications ii libdbd-mariadb-perl 1.22-1+b1 amd64 Perl5 database interface to the MariaDB/MySQL databases ii libmariadb-dev 1:10.11.1-2 amd64 MariaDB database development files ii libmariadb-dev-compat:amd64 1:10.11.1-2 amd64 MariaDB Connector/C, compatibility symlinks ii libmariadb-java 2.7.6-1 all Java database driver for MariaDB and MySQL ii libmariadb3:amd64 1:10.11.1-2 amd64 MariaDB database client library ii libmariadbd-dev 1:10.11.1-2 amd64 MariaDB embedded database, development files ii libmariadbd19:amd64 1:10.11.1-2 amd64 MariaDB embedded database, shared library ii mariadb-backup 1:10.11.1-2 amd64 Backup tool for MariaDB server ii mariadb-client 1:10.11.1-2 amd64 MariaDB database client binaries rc mariadb-client-10.6 1:10.6.11-2 amd64 MariaDB database client binaries ii mariadb-client-core 1:10.11.1-2 amd64 MariaDB database core client binaries ii mariadb-common 1:10.11.1-2 all MariaDB common configuration files ii mariadb-plugin-connect 1:10.11.1-2 amd64 Connect storage engine for MariaDB ii mariadb-plugin-cracklib-password-check 1:10.11.1-2 amd64 CrackLib Password Validation Plugin for MariaDB ii mariadb-plugin-gssapi-client:amd64 1:10.11.1-2 amd64 GSSAPI authentication plugin for MariaDB client ii mariadb-plugin-gssapi-server 1:10.11.1-2 amd64 GSSAPI authentication plugin for MariaDB server ii mariadb-plugin-mroonga 1:10.11.1-2 amd64 Mroonga storage engine for MariaDB ii mariadb-plugin-oqgraph 1:10.11.1-2 amd64 OQGraph storage engine for MariaDB ii mariadb-plugin-rocksdb 1:10.11.1-2 amd64 RocksDB storage engine for MariaDB ii mariadb-plugin-s3 1:10.11.1-2 amd64 Amazon S3 archival storage engine for MariaDB ii mariadb-plugin-spider 1:10.11.1-2 amd64 Spider storage engine for MariaDB ii mariadb-server 1:10.11.1-2 amd64 MariaDB database server binaries rc mariadb-server-10.6 1:10.6.11-2 amd64 MariaDB database server binaries ii mariadb-server-core 1:10.11.1-2 amd64 MariaDB database core server files ii mariadb-test 1:10.11.1-2 amd64 MariaDB database regression test suite ii mariadb-test-data 1:10.11.1-2 all MariaDB database regression test suite - data files ii mysql-common 5.8+1.1.0 all MySQL database common files, e.g. /etc/mysql/my.cnf ii python3-mysqldb 1.4.6-2 amd64 Python interface to MySQL $ find /etc -name '*mariadb*' -ls -or -name '*mysql*' -ls 45114 8 -rwxr-xr-x 1 root root 6387 Jan 18 09:40 /etc/init.d/mariadb 45118 4 -rw-r--r-- 1 root root 1859 Jan 18 09:40 /etc/logrotate.d/mariadb 42460 4 lrwxrwxrwx 1 root root 17 Jan 30 06:23 /etc/rc0.d/K01mariadb -> ../init.d/mariadb 42461 4 lrwxrwxrwx 1 root root 17 Jan 30 06:23 /etc/rc1.d/K01mariadb -> ../init.d/mariadb 42456 4 lrwxrwxrwx 1 root root 17 Jan 30 06:23 /etc/rc2.d/S01mariadb -> ../init.d/mariadb 42457 4 lrwxrwxrwx 1 root root 17 Jan 30 06:23 /etc/rc3.d/S01mariadb -> ../init.d/mariadb 42458 4 lrwxrwxrwx 1 root root 17 Jan 30 06:23 /etc/rc4.d/S01mariadb -> ../init.d/mariadb 42459 4 lrwxrwxrwx 1 root root 17 Jan 30 06:23 /etc/rc5.d/S01mariadb -> ../init.d/mariadb 42462 4 lrwxrwxrwx 1 root root 17 Jan 30 06:23 /etc/rc6.d/K01mariadb -> ../init.d/mariadb 42452 4 lrwxrwxrwx 1 root root 35 Jan 30 06:23 /etc/systemd/system/multi-user.target.wants/mariadb.service -> /lib/systemd/system/mariadb.service 10794 0 drwxr-xr-x 1 root root 148 Jan 30 06:43 /etc/mysql 10796 4 -rw-r--r-- 1 root root 8 Oct 20 2020 /etc/mysql/conf.d/mysql.cnf 10797 4 -rw-r--r-- 1 root root 55 Oct 20 2020 /etc/mysql/conf.d/mysqldump.cnf 10820 0 drwxr-xr-x 1 root root 336 Jan 30 06:43 /etc/mysql/mariadb.conf.d 11588 4 -rw-r--r-- 1 root root 231 Jan 3 06:42 /etc/mysql/mariadb.conf.d/50-mysql-clients.cnf 12552 4 -rw-r--r-- 1 root root 927 Jan 3 06:42 /etc/mysql/mariadb.conf.d/50-mysqld_safe.cnf 10819 4 -rw-r--r-- 1 root root 1126 Jan 3 06:42 /etc/mysql/mariadb.cnf 12541 4 -rw-r--r-- 1 root root 730 Jan 3 06:42 /etc/apparmor.d/usr.sbin.mariadbd 12545 4 -rw-r--r-- 1 root root 716 Jan 3 06:42 /etc/logcheck/ignore.d.paranoid/mariadb-server-10_6 45115 4 -rw-r--r-- 1 root root 716 Jan 18 09:40 /etc/logcheck/ignore.d.paranoid/mariadb-server 12547 4 -rw-r--r-- 1 root root 2153 Jan 3 06:42 /etc/logcheck/ignore.d.server/mariadb-server-10_6 45116 4 -rw-r--r-- 1 root root 2153 Jan 18 09:40 /etc/logcheck/ignore.d.server/mariadb-server 12549 4 -rw-r--r-- 1 root root 2153 Jan 3 06:42 /etc/logcheck/ignore.d.workstation/mariadb-server-10_6 45117 4 -rw-r--r-- 1 root root 2153 Jan 18 09:40 /etc/logcheck/ignore.d.workstation/mariadb-server $ dpkg -L mariadb-client-10.6 /etc /etc/mysql /etc/mysql/mariadb.conf.d $ dpkg -L mariadb-server-10.6 /etc /etc/apparmor.d /etc/init.d /etc/logcheck /etc/logcheck/ignore.d.paranoid /etc/logcheck/ignore.d.paranoid/mariadb-server-10_6 /etc/logcheck/ignore.d.server /etc/logcheck/ignore.d.server/mariadb-server-10_6 /etc/logcheck/ignore.d.workstation /etc/logcheck/ignore.d.workstation/mariadb-server-10_6 /etc/logrotate.d /etc/mysql /etc/mysql/mariadb.conf.d /etc/security I don't see anything problematic about this nor how this would differ from previous 'normal' upgrades from MariaDB 5.5 to 10.3 to 10.5 to 10.6 etc. The only problem there is that on purge deb-systemd-helper and update-rc.d will disable the service, but that is not based on package ownership.