Hi,
since initially it seems like the high load may be due to I/O wait
Maybe this will help you to identify the IO loading process:
http://dag.wieers.com/blog/red-hat-backported-io-accounting-to-rhel5
Thanks for the suggestion, I did install dstat earlier while trying to figure things out on my own. However, I think my kernel being the older version does not support the latest feature the website was pointing out. Given that it's a live server not within physical touch, I'm a little wary of doing kernel updates that might just kill it :D
I'll try other methods first and see if they help, if not, I'll probably have to bite the bullet and do it over a weekend where I get more time to repair any inadvertent damage.