UNIX for Dummies Questions & Answers

Hi,

I know there is a human readable mode of the 'df' command also known as 'df -h'. When I run that switch on most AIX boxes it doesn't work. My workplace currently has 10 AIX servers in which 2 can run df -h, but even a 'df' man page on those 2 boxes doesn't show any -h switch.

What is allowing these boxes to run the -h and not the others? How do I get them all to do so?

Regards,
Gui