excluding from tar

[D Golden]

I've created a tar archive of my entire system, but I want to exclude
everything in /proc , /usr/ports, and the FILE /usr/backup.tar when
updating the archive. I've tried:

1. cd / && tar -vu --file /usr/backup.tar * --exclude=/proc
--exclude=/usr/ports --exclude=/usr/backup.tar

2. cd / && tar -vu --file /usr/backup.tar * --exclude=/proc/*
--exclude=/usr/ports/* --exclude=/usr/backup.tar

3. cd / && tar -vu -X /root/nodump --file /usr/backup.tar *

and in /root/nodump I have 3 lines:

/proc   # Also tried /proc/*
/usr/ports  # Also tried /usr/ports/*
/usr/backup.tar

However, in all three examples, /proc , /usr/ports, and the FILE get updated.

What am I missing?

Dana