If I right click on a file in windows explorer, two file sizes are shown: "size" and "size on disk". Is the "size" the actual size of the file in bytes? Then the "size on disk" would be the "size" plus whatever number of bytes is necessary to align it to the size needed to store the file?

Posted on 2003-11-11 09:46:07 by Will
The "size" is exaclty how big the file is, the "size on disk" si how much space it occypoies on teh disc, for isntance on FAT32 disc the size on disc maybe (/often is) larger than the file size, since space can only be allocated in larger pices (clusters) - even if the file is smaller than one cluster it will occupy an entire cluster - thus waisting space.
But if you have a compresses fs (like NTFS with compression active), the file might take lesser space on the disc (since it's compressed).
So to shorten the answer, yes the "size on disc" can be considered "cluster aligned/padded size" (at leat for FAT discs).
Posted on 2003-11-11 14:30:56 by scientica

I figured as much.

Posted on 2003-11-12 09:50:53 by Will