One has to be careful in reading Moodle docs for Linux systems. Most describe Ubuntu and some CentOS. The link you gave, which might have confused you, was for Ubuntu. Not quite the same.
Here's the major diff: CentOS servers usually have DocumentRoot defined as:
/var/www/html/
In the config for the virtual apache server you have:
DocumentRoot /www/html/moodle_LZ
but when describing what has been done moodle is supposedly at:
/var/www/html/moodle
(those slashes are important, BTW)
The DocumentRoot line in the httpd.conf for the virtual host needs to reflect where you installed the moodle code: /var/www/html/moodle
You can check the httpd.conf file for syntax/errors using while in putty (ssh/terminal):
/usr/sbin/apachectl -t
That should respond with Syntax OK
After making changes to the httpd.conf file, Apache must be restarted:
/sbin/service httpd restart
from the terminal (ssh/putty).
Watch for errors when apache starts back up.
Your server should have curl installed, so use this as a quick test of the server:
curl -I http://internalipaddress |grep Server
In addition ... there is no external DNS entry for (this part you cannot do - up to IT):
www.diabetes.cmdn.dundee.ac.uk
The dig below is a DNS query for that host. Notice ANSWER: 0 - ie no response from DNS server for that hostname.
[root@sos moodle24]# dig www.diabetes.cmdn.dundee.ac.uk
; <<>> DiG 9.3.6-P1-RedHat-9.3.6-20.P1.el5_8.6 <<>> www.diabetes.cmdn.dundee.ac.uk
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 61964
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;www.diabetes.cmdn.dundee.ac.uk. IN A
;; AUTHORITY SECTION:
cmdn.dundee.ac.uk. 900 IN SOA ns0.lifesci.dundee.ac.uk. dnsadmin.lifesci.dundee.ac.uk. 1347543479 86400 7200 3600000 86400
For Moodle 2 to work there has to be an internal DNS entry as well and the CentOS server should be able to find itself in internal DNS.
So, to check that in terminal (ssh/putty):
dig www.diabetes.cmdn.dundee.ac.uk
Also, need to check to see if the CentOS server is running SELinux - by default it should be.
From putty (ssh/terminal) [case sensitive]:
fgrep 'SELINUX' /etc/selinux/config
If you see: SELINUX=enforcing
SELINUX will probably prevent Moodle from functioning.
Change that to SELINUX=permissive
nano /etc/selinux/config
After editing, save the file [CTRL][o] (control key then the 'o' key) and exit: [CTRL][x].
Changes to selinux require reboot of server.
reboot [ENTER].
'spirit of sharing', Ken