In order to transfer files larger than 2GB, you need to enable large file support on the samba server and mount the client side with the option lfs.
Server side:
/etc/samba/smb.conf
large readwrite = on
Client side:
mount -t smbfs -o username=remote_user,uid=local_user,rw,lfs //server/remote_user path_to_mount_point
