Hi.
If the external drive is already formatted with NTFS, then:
install fuse.
remove fuse-ntfs-3g
install ntfs-3g.
I had problems with fuse-ntfs-3g and those problems were resolved when I
swapped to straight ntfs-3g.
(CentOS 5.9). Mine was a 1TB external drive that was NTFS because it is
used on windows machines as well.
If you want to use your 3TB exclusively for for Linux, it might be ( as
suggested) ) best to change the partition to GPT and format it with
ext{3|4}.
-Andy