Why does my MySQL server suddenly not start. ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) [closed]
These are the most important messages:
2021-02-04T04:50:23.646339Z 0 [ERROR] InnoDB: Write to file ./ibtmp1failed at offset 11534336, 1048576 bytes should have been written, only 1032192 were written. Operating system error number 28. Check that your OS and file system support files of this size. Check also that the disk is not full or a disk quota exceeded.
2021-02-04T04:50:23.646348Z 0 [ERROR] InnoDB: Error number 28 means 'No space left on device'
I would guess that the disk containing your data directory is full.