Good morning Muhammad,

I have checked and I am using your mariadb.service file. For some reason, mariadb is failing to start.  We need to determine if the issue is coming from systemd or something in MariaDB datadir.


To start it without systemd, run:

/opt/mariadb/bin/mysqld --defaults-file=/opt/mariadb-data/my.cnf &
The below should work:
/opt/mariadb/bin/mysqladmin  --defaults-file=/opt/mariadb-data/my.cnf  -uroot -p version
/opt/mariadb/bin/mysqladmin  --defaults-file=/opt/mariadb-data/my.cnf  -uroot -p shutdown 


If the above does not work, you need to re-initialise mariadb:

kill the mysqld running as mariadb user. 
cd /opt/mariadb-data
cp -p my.cnf /tmp
rm -rf *
cp -p /tmp/my.cnf .
rm -rf *   # Attention data loss step
cd /opt/mariadb-10.2.14-linux-x86_64/
scripts/mysql_install_db --user=mariadb --defaults-file=/opt/mariadb-data/my.cnf


Otherwise its a systemd issue:
In that case can you provide the output of the following commands:

ps -ef | grep mysql
systemctl status mariadb
systemctl start mariadb 
ps -ef | grep mysql 
systemctl status mariadb  

Hope this helps
Kenneth


On Tue, May 15, 2018 at 10:05 AM, Muhammad Bashir Al-Noimi <mbnoimi@gmail.com> wrote:
On 05/12/2018 11:56 PM, Kenneth Penza wrote:

I have installed a new Ubuntu VM 16.04, installed MySQL 5.7 from Ubuntu repositories and MariaDB using the outline provided in the link https://ubuntuforums.org/showthread.php?t=2391680&p=13765881#post13765881 and got it working. 

The problem is stemming from the configuration files. By default, both MariaDB and MySQL read the options from /etc/mysql/my.cnf. A side effect of this is that the MariaDB installation under /opt is reading from  /etc/mysql that has the options for MySQL, which is causing all your errors. To get around this you need to use the "--defaults-file=/opt/mariadb-data/my.cnf" option with every MariaDB command. 
If you take a look into my snippet of /etc/systemd/system/mariadb.service you'll notice that I call --defaults-file with ExecStart property so I suppose it should work fine when I call systemctl start mariadb.service but it doesn't :(
https://gist.github.com/mbnoimi/5920301ff79dcb88aab3ef7fa459733e#file-mariadb-service-L19
ExecStart=/opt/mariadb/bin/mysqld --defaults-file=/opt/mariadb-data/my.cnf

# systemctl start  mariadb
# /opt/mariadb/bin/mysqladmin --defaults-file=/opt/mariadb-data/my.cnf  -uroot -p version
# /opt/mariadb/bin/mysqladmin --defaults-file=/opt/mariadb-data/my.cnf  -uroot -p version
Enter password:
/opt/mariadb/bin/mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/opt/mariadb-data/mariadb.sock' (2)'
Check that mysqld is running and that the socket: '/opt/mariadb-data/mariadb.sock' exists!
#

root@ubuntu:/etc/mysql# mysqladmin --defaults-file=/opt/mariadb-data/my.cnf  --print-defaults

# mysqladmin --defaults-file=/opt/mariadb-data/my.cnf  --print-defaults
mysqladmin would have been started with the following arguments:
--port=3308 --socket=/opt/mariadb-data/mariadb.sock
#
-- 
Best Regards,
Muhammad Bashir Al-Noimi
Skype+Telegram+GMail: mbnoimi