Q: MariaDB Installation Problem on Fedora 30 - mysql

Question

I need to install MariaDB and i follow the official Fedora Wiki instructions but i couldn't manage to do a proper installatiın though. So, first i run dnf install mariadb mariadb-server command (under root) and the return is
Package mysql-community-client-8.0.17-1.fc30.x86_64 is already installed.
Package mysql-community-server-8.0.17-1.fc30.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!
So i try to enable/start mariadb with systemctl start mariadb and then the return is
Failed to start mariadb.service: Unit mariadb.service not found.
I installed other essential packages like php, httpd, mysql etc. and i need to install LAMP too but I get this MariaDB error. Could you show me the way?

Answer 1

It happens because mysql-community packages are configured to obsolete mariadb packages.
The approach below might be not the most optimal, everyone is easy to pitch in to simplify it.
First of all, if you have mysql-community-* packages installed, you probably have MySQL Community repo configured. Search your /etc/yum.repo.d for it and remove it from there:
$ grep -ri community /etc/yum.repos.d/*
/etc/yum.repos.d/mysql.repo:[mysql80-community]
/etc/yum.repos.d/mysql.repo:name=MySQL 8.0 Community Server
/etc/yum.repos.d/mysql.repo:baseurl=http://repo.mysql.com/yum/mysql-8.0-community/fc/$releasever/$basearch/
sudo mv /etc/yum.repos.d/mysql.repo /tmp/
Then, check which exactly mysql-community-* packages you have:
$ rpm -qa | grep mysql-community
mysql-community-server-8.0.17-1.fc30.x86_64
mysql-community-libs-8.0.17-1.fc30.x86_64
mysql-community-client-8.0.17-1.fc30.x86_64
mysql-community-common-8.0.17-1.fc30.x86_64
The easiest way to get rid of them is just to remove them by dnf. But it needs to be done very carefully, because if they have been there for a while, you probably have other packages depending on them. So, when you run the remove command, make sure that you don't have an auto-yes (-y option), and examine the output before agreeing to uninstall. It might look somewhat like this:
$ sudo dnf remove mysql-community*
Dependencies resolved.
===================================================================================================================================================================================
Package Architecture Version Repository Size
===================================================================================================================================================================================
Removing:
mysql-community-client x86_64 8.0.17-1.fc30 #mysql80-community 66 M
mysql-community-common x86_64 8.0.17-1.fc30 #mysql80-community 8.3 M
mysql-community-libs x86_64 8.0.17-1.fc30 #mysql80-community 7.5 M
mysql-community-server x86_64 8.0.17-1.fc30 #mysql80-community 128 M
Removing dependent packages:
perl-DBD-MySQL x86_64 4.050-2.fc30 #fedora 367 k
Removing unused dependencies:
Note the section Removing dependent packages. I added only one package to make an example, but in your case it can be much longer and scarier. If you do have the section and don't know if you can safely remove all its contents, it maybe be better not to do it (just yet). Abort the operation.
Is this ok [y/N]: n
Operation aborted.
Instead, you can try to replace mysql-community packages with MariaDB. There is dnf option --allowerasing which seems to do the trick, but you need to specify package names with versions to work around mysql obsoleting (replace the version in the command with the actual version available by the time you are doing it):
$ sudo dnf install --allowerasing --setopt=install_weak_deps=False mariadb-server-10.3.17 mariadb-10.3.17
Last metadata expiration check: 0:07:18 ago on Mon 07 Oct 2019 02:25:32 PM UTC.
Dependencies resolved.
===================================================================================================================================================================================
Package Architecture Version Repository Size
===================================================================================================================================================================================
Installing:
mariadb x86_64 3:10.3.17-1.fc30 updates 5.9 M
mariadb-server x86_64 3:10.3.17-1.fc30 updates 17 M
Installing dependencies:
mariadb-common x86_64 3:10.3.17-1.fc30 updates 36 k
mariadb-connector-c-config noarch 3.1.3-1.fc30 updates 12 k
mariadb-errmsg x86_64 3:10.3.17-1.fc30 updates 205 k
mysql-selinux noarch 1.0.0-8.fc30 fedora 35 k
psmisc x86_64 23.1-5.1.fc30 fedora 133 k
Removing dependent packages:
mysql-community-client x86_64 8.0.17-1.fc30 #mysql80-community 66 M
mysql-community-server x86_64 8.0.17-1.fc30 #mysql80-community 128 M
Transaction Summary
Now nothing is removed as dependencies, apart from mysql-community, which was the goal.
The option --setopt=install_weak_deps=False is not strictly necessary, but without it dnf installs many packages which you probably don't need. You can run without the option to see the difference.
After you have replaced the server and client packages, you can check what else you have left from MySQL community server, and try to remove remaining packages if you want:
$ rpm -qa | grep mysql-community
mysql-community-libs-8.0.17-1.fc30.x86_64
mysql-community-common-8.0.17-1.fc30.x86_64
$ sudo dnf remove mysql-community-libs mysql-community-common
Dependencies resolved.
===================================================================================================================================================================================
Package Architecture Version Repository Size
===================================================================================================================================================================================
Removing:
mysql-community-common x86_64 8.0.17-1.fc30 #mysql80-community 8.3 M
mysql-community-libs x86_64 8.0.17-1.fc30 #mysql80-community 7.5 M
Transaction Summary
Now it seems safe, no dependencies anymore.
There is one catch I can think of. If you don't know why mysql-community was installed in the first place, it's possible that you have something which requires exactly it, and won't be satisfied with MariaDB replacing it. Then it probably won't allow you to replace the packages. But I can't guess what it could be, so it's up to you to try and see. I suppose it will show up in dnf output which you examine before confirmation.