Vista bug? Where is my 2GB?
 

I found this interesting after I started getting out of space errors on a HUGE drive. So I did a fresh vista test install on a new smaller drive, windows updates, antivirus and that's it. The picture attached shows a size discrepancy of close to 2GB in used space on C drive!!!

I have all files and folders UNhidden, including operating system files. THe recycle bin is empty and set to ZERO.

Anyone else see this issue?

My XP stole them!

Have a look - mine's different by 2GB but in the other direction. (May be Disk Properties value is an estimate?)

That's a HUGELY wrong estimate though...This could have an effect on how your NLE sees your space, wouldn't you agree?

Since I use a Mac maybe I don't understand the issue... Are you talking about the apparent difference between the 26,674,548,736 bytes vs 24.8 GB? If so then I suspect that has to do with the definition of a gigabyte and nothing to do with Vista eating your hard drive space. A Gigabyte isn't 1,000,000,000 bytes, it's 1,073,741,824 bytes - think "binary". If you multiply that by 24.8 you get 26,628,797,235 which is pretty close the what Vista is reporting.

You will find the same issue on the Mac as well. In fact, one of the hard drive manufacturers lost a class action lawsuit about deceptively advertising the capacity of their hard drives using these different measurements.

No, I'm referring to one properties window saying 7.27GB and the other saying 9.05GB. Being a techie this is not something I've seen in XP, 2000, NT4, or 9.x. Both shots were taken at the same time, no files where modified between the 3 seconds I brought up the properties of the drive vs. the properties of all the files on the drive...

I had a hunch that NTFS may be involved. Low and behold:

http://support.microsoft.com/kb/315688

There may be something in there, especially the hard links bit.

Seems this behaviour isn't just a Vista thing - I got a large discrepancy on one of my XP systems though in the opposite way.

Certainly an interesting puzzle....

Very interesting. I will have to do some more digging, since this is a fresh install on a new drive and I know my machine is running in top condition. 2GB is still WAY too much for this kind of mistake on such a small drive. Thanks for finding that.

Having read the Microsoft KB, I've just run some more measurements including chkdsk. A screenshot is attached. For the Disk Properties, I have converted the values in bytes to KB for easier comparison with the chkdsk output.

Here's the interesting stuff:

Disk Properties and chkdsk agree exactly with the total disk space
Disk Properties and chkdsk agree exactly with the free disk space

But:

Disk Properties and chkdsk do not agree with the used disk space

That seems very odd. chkdsk lists a number of other things so I decided to add them up. If you add the amounts in files, indexes, bad sectors and system use, you get the same value as the used disk space for Disk Properties. What the log file relates to and why it isn't used in the calculation for Disk Properties, I don't know.

The number of files reported is different between chkdsk and Explorer's Properties. I think chkdsk's indexes is equivalent to folders (based on the numbers).

Explorer's Properties are at odds with Disk Properties and chkdsk. Most odd is that Explorer's Properties reports that the total file size is larger than the size on disk.

It seems that Explorer's Properties is an approximation....

Crazy
 

Yes, I have been looking at my XP boots now too (both of them), only 296MB off between disk properties and file properties on one and 226MB on the other. That is reasonable considering file allocation and how the cluster sizing works. But 2GB in Vista on a fresh install, 30GB drive???? That is not acceptable. I checked both cluster sizes on those three disks and they are all the same.

I looked at my Vista installation and got the same behavior as XP:

Disk Properties and ChkDsk agree (if you add up ChkDsk's various contributions for used space. Explorer's Properties again seems to be an approximation. That was on the system partition which is NTFS.

I then looked at a USB flash drive which is FAT. I got the same behavior.

It doesn't seem to be a Vista thing. I wish I had a WIN2K installation to look at. I think Explorer's Properties is just an approximation (may be to speed up the determination compared to the more rigorous ChkDsk).

I pretty sure that when programs need to get the free space amount, they call a Windows API function that will behave like Disk Properties (which very quickly reports free space and is in agreement with ChkDsk). Of course, both could be calling the same API function.

Gotcha, ok. I still think it's weird that 2GB would be up in the air so to speak. None of my other install use that much emptiness...