18 domains serving out something lighter weight (WP/Joomla) isn't too many depending upon other package purchaces. But, like I said, Moodle 2 is a different 'beast' - resource hungry, DB 'heavy' (compared to those other popular open sourced packages mentioned ... of course, it does try to do more also).
So ... looking at http://www.compuwebhosting.com/vps-hosting.html
I see this statement:
'Our VPS nodes are divided into isolated containers that each have their own set of memory, diskspace and CPU power. One user simply can't bog down the entire server.'
So what are the specs of your CentOS system: version? 64 bit? Memory? Space? CPU's? and Bandwidth?
I see they also offer this:
"Free 3rd party installations. If you need a forum etc. installed we will take care of it "
That include Moodle 2.6.x?
When you embarked on this adventure, did you make a backup (sql dump) of the DB and tar ball (archive) the data directory as well as code directory?
Since you do have command line ... wonder if one could install 'git'. Git installations/upgrades are a breeze (no FTP) compared to the 'standard way' of upgrading a remotely hosted Moodle.
yum install git [ENTER]
http://docs.moodle.org/26/en/Git_for_Administrators
I do installs and updates as well as upgrades via git now. Only once had issues when the git repo server was having issues.
If trying to upgrade a 2.4 and take it to 2.6.x in your case is a little tricky, but can be done. Git cannot upgrade an already installed (manually) moodle. But, using a trick or two, one can work some command line 'magic' and 'get 'er done'!
'spirit of sharing', Ken
