I have not much experience with server administration, but i tried to execute unzip command in one particular directory on server and it hanged , it was not responding for long time. So I logged into the server through another terminal session and tried to enter in the same directory with cd command, but it also hanged. Eventually I logged into the server through another terminal session to kill those two processes. Somehow I was able to kill the unzip command process, but I am still not able to enter that directory. What is the issue?
Look in the "dmesg" output to see if there is any filesystem error. When I have this problem, normally is the disk that is offline or a disconnected nfs mount.
It was nfs issue and rebooting of servers resolved it.
When in doubt check the messages log first! Usually /var/log/messages, but not always depending on the system and application.