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File sizes reported by Explorer

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I’ve been trying to get a definitive answer for this one: When viewing a file or folder properties, why are two sizes often shown? For example, FileA will show “Size: 173KB (177,152 bytes), 196,608 bytes used”. At first I thought this was an issuewith the NetWare file system, but then realized that this is true of local files and folders. Is this difference due to file allocation methods and the unused space that can result?

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File sizes reported by Explorer

In reply to File sizes reported by Explorer

The first number is the file size and the second number is the reference to the number of bytes used on the disk in a particular cluster,it will grow by association with hidden files for example.

File sizes reported by Explorer

In reply to File sizes reported by Explorer

I’ve never heard the “grow by association with hidden files” theory. Can you elaborate?

File sizes reported by Explorer

In reply to File sizes reported by Explorer

You don’t really see 2 different sizes for your files or folders. 173KB is equal to 177,152 bytes. What is shown is the size of the file in two different units.
1KB is equal to 1024 bytes (ie. if you divide 177,152 by 1024 you would get 173)
It’s the same as saying the length of a stick is 12 inches or 1 foot.

Jeff

File sizes reported by Explorer

In reply to File sizes reported by Explorer

Thanks for putting in your 2 cents, but you didn’t read my question carefully.

File sizes reported by Explorer

In reply to File sizes reported by Explorer

The first number represents the actual total bytes these files are in size. The second number represents the actual total bytes plus the slack space (or total bytes of all clusters used). Slack space is space at the end of each cluster that’s not used.

Your HD is organized into a certain number of clusters times the cluster size. The number of clusters and cluster size is based on HD size and file type used (FAT, FAT32, NTFS, etc). DOS/Windows allocate space for files using whole clusters. Example: if you have a 6 gig hard drive, and use Win98 with FAT32, your cluster size is 4096. When you save a 323 byte file, the OS will allocate one whole cluster to store it. The actual space used is only 323 out of 4096. The rest of the space in that cluster is wasted and called slack space. That slack space is not usable by another file.

File sizes reported by Explorer

In reply to File sizes reported by Explorer

I remember when the slack used to be called “overhang”. Thanks for confirming what I suspected.

File sizes reported by Explorer

In reply to File sizes reported by Explorer

As noted, this difference represents “slack space” at the end of the last cluster. Average “waste” space on a disk is # of files times 1/2 cluster size. Your example suggests you’re using 32K clusters. You might want to consider changing to FAT32 and regaining a LOT of disk space…

File sizes reported by Explorer

In reply to File sizes reported by Explorer

My work PC runs under NT4 so FAT32 is out of the question. However, your response gives me an idea. I’m going to do some comparisons of “slack” under FAT and NTFS.

[Author]

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