You almost surely do not want that. qw// splits its arguments on whitespace, so you will get an array whose 0th item is "/media/disk", not /media/disk. You can use qw// without the quotes, or drop qw// and insert commas to just construct a list directly, to get what you probably expect.

UPDATE: On further thought, notice that constants are functions, not scalars or arrays (which is why you can't interpolate them). Thus, while you can probably export them using Exporter, it's a function (hence must be exported as a bareword, or with preceding &), not an array, that you'll be exporting. As others have mentioned, it's probably more straightforward just to make it a package variable (with our) so that you can export it directly.