Any file end with .php no working on my server, some time working but very slowly.
Also when I checked Sever Status > Service Status by WHM I see red color front of Disk /hda6 (/var).
Any one can help me to fix this problem.

Thank you.

Sounds like your /var drive is full

You should probably go in and wipe out some old logs that you don't need anymore.

Try looking at "top" to see what else could be causing the slow downs..

Does sound like your /var drive is to small.. May need to make that bigger some how..