MySQL won't start. What reasons?

Question

MySQL

Hello! Mysql won't start after server restart. I can't figure out what the problem is from the logs.

[email protected]:/home/d4mwww# systemctl start mysql
Job for mysql.service failed because the control process exited with error code.
See "systemctl status mysql.service" and "journalctl -xe" for details.

[email protected]:/home/d4mwww# systemctl status mysql.service
● mysql.service - MySQL Community Server
     Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Mon 2021-07-26 17:23:16 +07; 25s ago
    Process: 8948 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
    Process: 8956 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)
   Main PID: 8956 (code=exited, status=1/FAILURE)
     Status: "Server startup in progress"
      Error: 2 (No such file or directory)

Jul 26 17:23:16 tomskmarathon.ru systemd[1]: mysql.service: Scheduled restart job, restart counter is at 5.
Jul 26 17:23:16 tomskmarathon.ru systemd[1]: Stopped MySQL Community Server.
Jul 26 17:23:16 tomskmarathon.ru systemd[1]: mysql.service: Start request repeated too quickly.
Jul 26 17:23:16 tomskmarathon.ru systemd[1]: mysql.service: Failed with result 'exit-code'.
Jul 26 17:23:16 tomskmarathon.ru systemd[1]: Failed to start MySQL Community Server.

Jul 26 16:48:02 tomskmarathon.ru systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
-- Subject: Unit process exited
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
-- 
-- An ExecStart= process belonging to unit mysql.service has exited.
-- 
-- The process' exit code is 'exited' and its exit status is 1.
Jul 26 16:48:02 tomskmarathon.ru systemd[1]: mysql.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
-- 
-- The unit mysql.service has entered the 'failed' state with result 'exit-code'.
Jul 26 16:48:02 tomskmarathon.ru systemd[1]: Failed to start MySQL Community Server.
-- Subject: A start job for unit mysql.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
-- 
-- A start job for unit mysql.service has finished with a failure.
-- 
-- The job identifier is 2720 and the job result is failed.
Jul 26 16:48:02 tomskmarathon.ru systemd[1]: mysql.service: Scheduled restart job, restart counter is at 5.
-- Subject: Automatic restarting of a unit has been scheduled
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
-- 
-- Automatic restarting of the unit mysql.service has been scheduled, as the result for
-- the configured Restart= setting for the unit.
Jul 26 16:48:02 tomskmarathon.ru systemd[1]: Stopped MySQL Community Server.
-- Subject: A stop job for unit mysql.service has finished
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
-- 
-- A stop job for unit mysql.service has finished.
-- 
-- The job identifier is 2798 and the job result is done.
Jul 26 16:48:02 tomskmarathon.ru systemd[1]: mysql.service: Start request repeated too quickly.
Jul 26 16:48:02 tomskmarathon.ru systemd[1]: mysql.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
-- 
-- The unit mysql.service has entered the 'failed' state with result 'exit-code'.
Jul 26 16:48:02 tomskmarathon.ru systemd[1]: Failed to start MySQL Community Server.
-- Subject: A start job for unit mysql.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
-- 
-- A start job for unit mysql.service has finished with a failure.
-- 
-- The job identifier is 2798 and the job result is failed.

Answer 1

It looks like there is no free disk space. Check:
df -h

Answer 2

right as usual was not enough