i have the problem, that i would like to search for a file only on SDA not on any mounted NAS-Drives.

there should be some filter:

find /dev/sda -name *filename*; # only search on sda, this is just an example command! ITS NOT GOING TO WORK!

this is way too complicated -> http://stackoverflow.com/questions/4210042/exclude-directory-from-find-command

all the examples there do not „cut it“.