Drive properties misreporting used space

[watercooled]

I've just checked drive properties for C: and it says 18GB used (on a fresh install with a few apps) but when I check total file size of all the folders in the drive it says they total 21.7GB. I could understand if it was the other way round because of hidden system files etc but what's going on here? I've run chkdsk /f but it didn't make any difference.

[Infinite]

http://windirstat.info/

Try this for the lulz

[watercooled]

I've actually already tried windirstat, it reports about the same as selecting all the files. I just can't think why drive properties is reporting around 3 gigs less.
Here's a screenshot if it helps:


Everything looks about right in Ubuntu though...

[watercooled]

I've just been thinking maybe the file size is more of an estimate than an actual measurement after all there are hundreds of thousands of files in the Windows directory. All the folders on C: (including any system folders) measure about 17.4GB on Ubuntu - maybe that's a more accurate measurement. Also drive space used is at 17.8GB until a few minutes after the PC has booted and I've been using it when that changes to 18GB.

[dshepsman]

it could be temp files, swap files, windows system restore points.... that kind of thing.
plus, a file can be x in size (say 40kb), but the amount of actual disk space used will be more (512kb - but will vary due to the file system, eg ntfs, fat 32 etc etc)

[Singh400]

Show hidden files and folders, as well as system files as folders.

I'm thinking page file + some system files/folders.

[watercooled]

No check it again it's the other way round. The size of all the files is apparently greater than used drive space under Windows. My PF isn't on C: either.

[jim]

Yeah it looks fairly obvious what's wrong at first reading

I just checked and all my files together plus what's being used for system restore also equals more than the space my drive reports as being used, so I suspect it's something similar to what you're suggesting.

[watercooled]

Oh right. Well I'm glad it's not just me then. I've been moving hundreds of GB around in the past few days and I thought the filesystem might have been damaged/corrupted in some way. Maybe Windows doesn't report file size properly for so many files.

Thanks for replying everyone!

[TheAnimus]

Hmm i would of thought it was compressed files at first.

But then after seeing the size on disk, i don't think that is the case.

It could be possible thou, in NT that you've got junctions or mounted drives as folders that are outside that partition, and been included in that space?

[shaithis]

Wasted space?

Do you have a ton of small files, combined with a large allocation unit size?

[speardane]

cross-linked files?

might be interesting to scan the disk...

[watercooled]

Err I'm not sure. It wasn't far off a clean install when I made the thread so I think most of the used space was the Windows folder, which does have thousands of small files. I was thinking cross-linked files or something might be the cause but how would I check?
Thanks