@Everblue
So, if I try to copy copy filies in the HDD, once it goes over the 3gigs, will it give me an error that the HDD is full, or it will copy everything regardless?
It depends on the application. Most (including Workbench and Copy CLI-command) do not perform any "is the disk becoming full?" -checks but rather trust the filesystem to report an error once full. As such they will work just fine with any filesystem size (even though Workbench reports the filesystem total and free capacity wrong).
If the application does perform these checks, it usually depends on the age: Older apps mostly fail in this fashion (back then no one expected HDDs sizes to grow over 4GB...). New applications should not have this problem.
Anyhow, if you do get the problem you can use Workbench or Copy command to "workaround" the issue as described in the earlier post.