Can't start mysql server after updating Ubuntu 18.4 - mysql

Question

first i have tried to uninstall both of them
root#thaali:/etc/mysql# sudo apt-get remove --purge mysql*
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package mysql.cnf
E: Couldn't find any package by glob 'mysql.cnf'
E: Couldn't find any package by regex 'mysql.cnf'
E: Unable to locate package mysql.conf.d
E: Couldn't find any package by glob 'mysql.conf.d'
E: Couldn't find any package by regex 'mysql.conf.d'
Then i have tried to install them
root#thaali:/etc/mysql# sudo apt-get install mysql-server mysql-client
Reading package lists... Done
Building dependency tree... 50%
Building dependency tree
Reading state information... Done
mysql-client is already the newest version (5.7.26-0ubuntu0.19.04.1).
mysql-server is already the newest version (5.7.26-0ubuntu0.19.04.1).
0 upgraded, 0 newly installed, 0 to remove and 13 not upgraded.
This is what happen when i tried to restart
root#thaali:/etc/mysql# sudo service mysql start
Job for mysql.service failed because the control process exited with error code.
See "systemctl status mysql.service" and "journalctl -xe" for details.
This is what happened when i try to systemctl
root#thaali:/etc/mysql# systemctl status mysql.service
● mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; bad; vendor preset: enabled)
Active: failed (Result: exit-code) since Wed 2019-05-29 22:07:43 +0530; 6min ago
Process: 21283 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=1/FAILURE)
මැයි 29 22:07:43 thaali systemd[1]: mysql.service: Control process exited, code=exited, status=1/FAILURE
මැයි 29 22:07:43 thaali systemd[1]: mysql.service: Failed with result 'exit-code'.
මැයි 29 22:07:43 thaali systemd[1]: Failed to start MySQL Community Server.
මැයි 29 22:07:43 thaali systemd[1]: mysql.service: Service RestartSec=100ms expired, scheduling restart.
මැයි 29 22:07:43 thaali systemd[1]: mysql.service: Scheduled restart job, restart counter is at 5.
මැයි 29 22:07:43 thaali systemd[1]: Stopped MySQL Community Server.
මැයි 29 22:07:43 thaali systemd[1]: mysql.service: Start request repeated too quickly.
මැයි 29 22:07:43 thaali systemd[1]: mysql.service: Failed with result 'exit-code'.
මැයි 29 22:07:43 thaali systemd[1]: Failed to start MySQL Community Server.
This is the error that's throw me when i tried to connect
root#thaali:/etc/mysql# mysql -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
Can any one please help me to solve this and i have seen in some places i have edit etc/my.cnf to fix this in my case i don't have such a file

Answer 1

This one is really weird for I was not dist upgrading. One day it just didn't work.
When I tried journalctl -xe I got this
...
Oct 05 08:51:26 <servername> mysql-systemd-start[10914]: ERROR: Unable to start MySQL server:
Oct 05 08:51:26 <servername> mysql-systemd-start[10914]: mysqld: Error on realpath() on '/var/lib/mysql-files' (Error 2 - No such file or directory)
...
I fixed it by doing this:
sudo mkdir /var/lib/mysql-files
sudo chown -R mysql:mysql /var/lib/mysql-files/
sudo chmod 700 /var/lib/mysql-files/
sudo service mysql restart
Restarting the service didn't actually fix all problems I was having so I ended with rebooting the machine.