Earlier quoted context omitted.
Thank you for commenting here! I am curious. Can you be a little specific and tell us what Linux or Unix experience do you have? I mean can you specify the Linux distro names and the Unix brand names (AIX, Solaris, etc.) that you have worked with?
wait do people actually think this position requires Unix (not linux) experience? I assumed the recruiter must just be wrong there.
For example, American Express has a large deployment of AIX systems and they indeed look for candidates with experience in AIX systems, although I believe someone with experience in another Unix or Unix-like system should also be okay.
But I agree that such openings are usually quite specific about which Unix system they are working with.