[CentOS] MySQL Can't create file '/tmp/#sql2e0_98_0.frm' (errno: 9) problem

Hi.

I have a strange problem.

I installed cacti, and set it up.

When I click on the Plugins Management, I noticed Error "FATAL: Database or Table does not exist"

Further testing revealed that at the moment MySQL can not create temporary files in /tmp. It is same for ANY database!

SELinux is disabled. I logged to mysql as root and error is same.

Command used is: CREATE TEMPORARY TABLE IF NOT EXISTS plugin_temp_table LIKE bak_menu;

Error is: ERROR 1004 (HY000): Can't create file '/tmp/#sql21f8_f3_0.frm' (errno: 9)

What could be the problem, any idea how to proceed?

I do not think I edited any MySQL setting.