Linux is running out of memory space, probably because mysql has so many databases that you can just delete a few.
Or first CD.. Cut to the root directory
Find the one that takes up the most space

du -sh *

mine is the largest var directory

cd /var   //Enter the var directory
du -sh * //continue to find which folder is the largest with the command

also found that the lib folder in the var folder took up a lot of space

cd /lib   //Enter the lib directory
du -sh * //continue to find which folder is the largest with the command

eventually found out that my mysql was using 13 Gigabytes
cut into mysql, deleted the big library, just fine.
I’m with the library, you might have a cache or log log problem, check it slowly with the do -sh * command