Hard drive showing 333 MB of used space even though there are no files?

Question

I've been using an external hard drive for quite some time, and recently I've upgraded to an internal drive and therefore moved all of my files from the external hard drive to the internal one.

Now my external hard drive is (obviously) empty. But at the same time it's not.

For some reason Windows and also Linux still show around 333-336 MB of used space, even though the drive is completely empty.

Yes, I am viewing hidden files. Yes, I am also viewing protected system files. The only 2 folders remaining were a Recycle Bin folder, which is empty, and the System Volume Information folder.

So I went ahead and booted into Ubuntu, deleted both folders (which were only 1 MB in total), pressed CTRL+H in the file manager to view hidden files and yes, the drive is now really empty (some weird Trash folder appeared which I can't delete but its less than a KB big).

Yet Windows and GParted still say that 333 MB is in use.

How can that be?

The external HDD is made by Western Digitals, has 500 GB total space, and the partition is 500 GB big (NTFS).

Here's a screenshot:

In Windows 7:

Solution

NTFS allocates a hidden data-structure for it's meta-data.
For a 500 GB partition this will be around 350 MB when the NTFS format is done with default settings.
So this is completely normal. This is just the way NTFS was designed.
The only way to get rid of it is to re-format with another filesystem.

Comments

[Frank Thomas]

Its filesystem metadata structure. The Trash folder is caused by mounting the disk in linux. the 1000 is the userID of the first user created on the box.

[Minegem]

So you're saying that the 333 MB are the filesystem's metadata structure? If so, why would it be 333 MB? What is there so much to store? I mean the drive is completely empty after all (except for that Trash folder).

[Frank Thomas]

NTFS's metadata structure is "filled" even when empty. The idea is that adding additional information to the metadata will not affect the size on disk. If the disk is very full, you wouldn't want to lose the ability to rename a file to have a longer name or create a junction or whatever. by preallocating the storage, file system operations are ensured to have space to work with even if the disk is completely full.

[Minegem]

Interesting. So I just went ahead and removed the entire partition table and created a new 500 GB partition using Diskpart in Windows. Now the drive is showing 103 MB of used space. Why does it differ now? It was 333-336 MB before and now it's 103 MB. In both cases the partition was empty.

[Ramhound]

@Minegem - The size of the table likely was larger then 103 MB when you started to delete files, so it zero filled the table, but the size reserved was simply larger then 103 MB.