Disk usage is calculated based on the size of files and directories stored on a filesystem. Here’s a brief overview of how it works:
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File Size: Each file has a size, usually measured in bytes. This is the actual amount of data the file contains.
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Block Size: Filesystems allocate space in blocks. A block is a fixed-size unit of storage (commonly 1KB, 4KB, etc.). Even if a file is smaller than a block, it still occupies one full block.
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Calculation:
- For each file, the disk usage is rounded up to the nearest block size. For example, if a file is 2KB and the block size is 4KB, it will occupy 4KB on disk.
- The total disk usage for a directory is the sum of the disk usage of all its files and subdirectories.
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Metadata: Additional space may be used for filesystem metadata, such as inodes, which store information about files (permissions, ownership, etc.).
Example:
- If you have:
file1.txt(3KB) → occupies 4KB (1 block)file2.txt(2KB) → occupies 4KB (1 block)
Total disk usage = 4KB + 4KB = 8KB.
If you have further questions or need clarification, feel free to ask!
