Constant HDD activity
Good day, I'd like to ask for your help concerning a problem with my ISPConfig 3 server.
It's a "perfect setup"-based 64-bit CentOS 5.7 server.
For a long time everything was perfect. Then yesterday I noticed that the server started to operate very slowly. I mean, VERY SLOWLY - a few minutes for a simple web page to load, having to wait a lot for the login/password prompt while connecting by ssh, etc.
I also noticed that the HDD led was showing constant disc activity.
I rebooted the server, and the booting process looked normal (fast, no errors), but shortly afterwards (1-3 minutes) this unusual hard disk activity was back, and the server was again slow.
I "yum updated" to the latest versions of the software packages, and I also updated to the latest version of ISPConfig. (I have to say that I had to do "yum update" step by step, package by package, because, as I said, I had about 2 minutes of normal server operation upon reboot, after which even yum update took ages.
ISPConfig update went smoothly, without errors.
Now I have all the latest software, but the problem is still here. Like I said, there are no errors during the booting process - and it's as fast as it was earlier. Also, the server is fairly new, with 8 gigs of RAM and a lot of free hard disc space.
I wonder what could be causing this HDD activity? Is there a way to monitor it?
I tried stopping crond, but the HDD led is still flashing.
Please kindly help me to find out what's causing the problem.