Failed to open /etc/webmin/apache/site for writing : No space left on device

I have virtualmin installed on a 4core server which has 2tb of harddisk

3 wordpress sites installed and 20gb for the system but the local disk space was growing up everyday as 4 - 5%, so yesterday was 44% and today I got the messagge
Failed to open /etc/webmin/apache/site for writing : No space left on device

Im running centos 6.8 server but Im very confused because of this problem if anyone knows how to resolve or if the webmin has any cache deposit please let me know to clear cache files or how to resolve this problem

thankyou

php stopped working apache and everything so no one can login in my site,Im fraid to lost any data please any help is very appreciated

I have just used the command sudo rm -rf /var/cache/yum/x86_64/6/$REPONAME
and now I can access in webmin so the local disk space now is 50% but I restarted apache and apache failed to start

When I click on virtual server manage database now Im getting the messagge below:

/usr/bin/mysqlshow: Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’ (2)

:frowning: