How can the size on disk be smaller than size?

Question

I have an xml file that windows explorer says is 8.00KB on disk, and the size is 25.5 KB.

How is this possible?

I thought the size on disk is in many cases larger than the actual size (because of the block sizes)?

score 20 · Answer 1 · answered Dec 12 '12 at 17:10

20

This would happen if you use NTFS compression to compress the file.

answered Dec 12 '12 at 17:10

SLaks

8,024

score 9 · Answer 2 · answered Dec 12 '12 at 17:12

9

You are correct that the size on disk is normally larger. However, sometimes, due to built in compression, the file is actually smaller on the disk.

Source

answered Dec 12 '12 at 17:12

David

9,854

Brian · Answer 3 · 2018-07-05T19:55:04.853

3

A file can also appear to be smaller on disk if the file is a sparse file. In that scenario, file size refers to the logical size of the file, whereas size on disk refers to the physical size of the sparse file.

edited Jul 05 '18 at 19:55

answered Dec 18 '17 at 17:12

Brian

308

score 1 · Answer 4 · answered May 14 '21 at 16:11

1

If you're using Microsoft OneDrive and some of your files are 'not synced' to disk, then the size of the file on disk will be smaller since the actual information is in the 'cloud' on OneDrive with only a pointer.

answered May 14 '21 at 16:11

user2533577

19

How can the size on disk be smaller than size?

4 Answers4

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