ok i rebooted the machine and changed the password in single user mode. it worked perfectly.

However my problem is a little more extensive than this (as usual)

I have the same root passwd on all 4 of my servers. All running Red Hat Linux.

For some odd reason the root passwd will not work on any of my servers. It looks like someone manually changed the root passwd on all my servers (sounds like a hacker).

My question is there a way to change the root passwd on all of my servers without having to reboot every single one of them or creating boot disks ?

The reason i dont want to reboot these servers is because they are production web servers.