Mac external drive, file rights I have a mac that just received an external drive which I formatted and plugged in.

When I am logged in as a normal user it all looks fine.
But when I am logged in as root the system recognizes ownership of the drive as '_unknown'.
Also, I can't change the ownership of any files/folders within the drive to root.
I do 'sudo chown root somefolder' but nothing happens.

Why is this happening? How can I make the mac recognize the external drive correctly?

Further info:
Version: OSX 10.7.5.
External drive is connected via USB.
It's a 3TB externa Lacie drive.
I formatted the external drive by just clicking the 'Lacie setup' program that appears when you connect it.
Filesystem: when i typed mount i recieved (hfs,local,nodex.noswich.journaled).
In the Finder, get info on the volume (under the File menu). First, check the General section of the info window to make sure it's in one of the Mac OS Extended formats (probably "Mac OS X Extended (Journaled)"); if not, you'll need to reformat it. I'm not familiar with the Lacie setup program, but you can use Disk Utility to do this.

If it's in Mac OS X Extended format (or a variant), expand the Sharing &amp; Permissions section of the info window, and see if it has an "Ignore ownership and permissions" option at the very bottom. If it's there and enabled, click the padlock and authenticate as an administrator, then disable the "Ignore..." option.

Explanation: when OS X sees a new external volume, it assumes it's either come from another computer, going to another computer, or both.  Since there's no general correspondence between accounts on different computers, OS X figures there's no point in trying to track file ownership and simply disables it. If you enable ownership in the Info window, OS X will start storing &amp; respecting ownership on files on that volume.