Is it possible to use a linux machine and then use and IRIX system without any problems?? Is the commands, utilities etc almost the same on both of the systems??? If you're familiar with linux is it then possible to "port" your knowledge to irix??
UNIX is UNIX, so the concepts and most commands are the same. However, I doubt you could simply walk up to the other type of system and have total control. However, your skills from one will certainly make it much easier to understand the other with the proper documentation or instruction.
If you want a real "SGI experience" from your Linux machine, switch your default shell from bash to csh ('cause that's what SGI uses), then install the Linux port of the Indigo Magic Desktop: