Did you really mean to say ‘name of drive’? The .plexignore file does not work on drives, it works on folders and files relative to the folder that the .plexignore file is located in.
My folders are added to the .plexignore file, but when I go to the Plex Media Server and try to locate the folder for my movies, I am still able to see it.
.plexignore is used by PMS to skip scanning those items for addition to the library. I don’t believe it has any impact at all when browsing for folders in the Library setup area if that’s what you are referring to. It simply filters out those files and folders from being ADDED to the Library.