A continuation of Check_mk and FreeNAS, Pt. 1.
So I've got my check_mk on set up on my NAS, and it's monitoring stuff beautifully. However, it's not monitoring something very near and dear to my heart for this server: S.M.A.R.T. data. FreeNAS comes with smartctl, and there's already S.M.A.R.T. data plugins for the linux agents, so I figured this wouldn't be a big deal. And I was right! All I had to do was add the following script to my plugins/ folder for check_mk to find, and the server picked it up automatically.
The linux script has a lot fancier checking for edge cases. I figured FreeNAS would be homogeneous enough that it wouldn't be worth converting all those edge cases, so this is a very simple script, shared on a "works for me" basis.