Taibok

I've been using unRAID for a few months, and am having a problem with one of my disks. I can't seem to get it to spin down. Even manually spinning down all disks with the unMenu option leaves disk5 spun up. I'm currently using 5.0.5 I tried using inotify, installing the package based on the instructions I found in this post http://lime-technology.com/forum/index.php?topic=17449.msg157730#msg157730 but when I go to invoke the inotifywait -rw /mnt/disk5 command, I get "-bash: inotifywait: command not found". I'm not sure what I'm doing wrong. Is there a step I'm missing to use this command? Is there anything else I could do to check why one particular disk in my array is staying spun up? I'm relatively computer savvy, but a complete noob to Linux in general. Thanks.