I have a server that runs Debian 6.2, with Apache, PHP5, and MySQL.

Well, I hadn't done anything with MySQL at all so far, just Apache and PHP; I must have installed it (mysql-server) at some point along the line, and I decided to login to the database for the first time a couple days ago as I was considering using the database for a future website project.

I noticed that the "root" user had a password, and I didn't recall having set one. My usual root password was incorrect. So I attempted to reset the password.

sudo service mysql stop

(stopped successfully)

sudo /usr/bin/mysqld_safe --skip-grant-tables --skip-networking &

started successfully, from what I can tell. However,

mysql

itself returns "Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld,sock' (2)", and additionally

sudo service mysql start

returns "/etc/init.d/mysql: ERROR: The partition with /var/lib/mysql is too full! ... failed!"

df -h tells me that / is 26% used, a 20GB partition, and /home, roughly 900GB, has only 5% usage.

On a potentially related note, I've been experiencing random hangs since I noticed this problem, my tty2 randomly froze several times while idle, and the entire system is suddenly unstable. gnome-terminal also does not open. (Gnome-terminal apparently works now, disregard that part, but the server is still being somewhat unstable, I randomly lost connection when I was SSHed into it from my laptop, twice now.)