File size is a measure of how much data a computer file contains or how much storage space it is allocated. Typically, file size is expressed in units based on byte. A large value is often expressed with a metric prefix (as in megabyte and gigabyte) or a binary prefix (as in mebibyte and gibibyte).
Slack space
Due to typical file system design, the amount of space allocated for a file is usually larger than the size of the file's data – resulting in a relatively small amount of unusable storage space for each file, called slack space or internal fragmentation.
Generally, a file system allocates space in blocks that are significantly larger than one byte. The file system allocates a number of blocks that together provide enough space to hold the file data. Unless, the file fits exactly into the aggregated blocks, then some storage space is unused.
A file's allocated storage size is sometimes referred to as file size or alternatively with qualification such as size on disk.
See also
References
- JEDEC Solid State Technology Association (November 2019). "Terms, Definitions, and Letter Symbols for Microprocessors, and Memory Integrated Circuits". JESD 100B.01. p. 8. Retrieved 2009-04-05.
- "What is Slack Space?". IT Pro. 2010-01-19. Retrieved 2018-02-17.
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| Computer files | |
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