cPanel. Why is the partition in the system constantly overflowing?

Question

Domain Name System

Hello!
Problem: The partition in the system is constantly overflowing.
Options:

uname -a
Linux myhostname(заменен) 2.6.18-92.el5 #1 SMP Tue Jun 10 18:49:47 EDT 2008 i686 i686 i386 GNU/Linux

CENTOS 5.10 i686
cPanel WHM Accelerated 2 (WHM 11.38.2 (build 12)
Now some commands:

@host [/]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda5             3.0G  805M  2.0G  29% /
/dev/sda8             119G   44G   69G  39% /home
/dev/sda7             996M   50M  895M   6% /tmp
/dev/sda3             4.9G  4.5G  186M  97% /var
/dev/sda2              15G  8.1G  5.7G  59% /usr
/dev/sda1              99M   11M   83M  12% /boot
tmpfs                 506M     0  506M   0% /dev/shm

As you can see, the /var section is overflowing.
Let's look into /var itself

@host [/]# du -h --max-depth=1 /var
92K     /var/profiles
20K     /var/yp
521M    /var/cpanel
4.0K    /var/cvs
32K     /var/empty
17M     /var/tmp
27M     /var/cache
24K     /var/portsentry
8.0K    /var/racoon
1.1M    /var/run
12K     /var/account
40K     /var/lock
20M     /var/spool
24K     /var/db
16K     /var/lost+found
8.0K    /var/opt
8.0K    /var/preserve
1.2G    /var/named
8.0K    /var/games
189M    /var/log
8.0K    /var/local
8.0K    /var/nis
8.0K    /var/crash
2.3G    /var/lib
4.2G    /var

Here we see suspicious objects by volume:
521M /var/cpanel
1.2G /var/named
189M /var/log (not very suspicious, because logs really fly there)
In addition, mysql from var was stolen a long time ago, so the place is here he doesn't take much.
In the /var/ cpanel
folder there is a folder
450M /var/cpanel/perl
So the first question is: Can this be deleted? what is it for? or what to do with it?
in the /var/name/data folder there is a file
-rw-rw---- 1 named named 1.2G Dec 26 18:17 named.run
It seems to be for debugging the BIND service, and if I start the service with a lower debug level, then does it shrink?

Answer 1

If there is not enough information for a hint ^_^ I will throw more on demand.