Thank you all! I will follow up what you said here this weekend
By the way, I've created a regular account and tried to "su root" from it, but failed.
This system was a property of a big US company like Home Deport, Sears. I really don't know why they didn't wipe out the hard disks before selling it. Before reinstalling AIX, I want to learn its settings. Make sense?
You are so nice. You all have a great weekend