How to ask for something (twice) without being a pain?

OK, so at work I have a project which I have to get done before I move on to the really cool part of my job. In order to finish it, I need the sysadmin to set something up for me (root access is required). The problem is, it’s been almost a week and he may have forgotten, and my manager is starting to bug me about it. I don’t want to come off as rude when I talk to the admin because he’s a really busy guy (and I’m an intern working on a side project), and he seems pretty nice. So what I’m asking is, how can I get what I want without looking like a jerk? Thanks!