Files use disk blocks as the basic units of storage on a filesystem. Here's how it works:
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Disk Blocks: A disk block is a fixed-size chunk of disk space, typically ranging from 512 bytes to several kilobytes (e.g., 4 KB). The size of the block is determined by the filesystem.
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File Storage: When a file is created, it is stored in one or more disk blocks. If the file size is smaller than the block size, it will still occupy one full block. For example, a 1 KB file will use one 4 KB block, leaving 3 KB unused.
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Fragmentation: If a file grows larger than the available space in its original block, it may be split across multiple blocks. This can lead to fragmentation, where parts of a file are stored in non-contiguous blocks, potentially affecting performance.
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Directory Entries: Directories themselves are also stored in disk blocks. Each entry in a directory (which points to a file or subdirectory) takes up space in a block.
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Free Space: When files are deleted, the blocks they occupied are marked as free and can be reused for new files. The filesystem keeps track of which blocks are in use and which are free.
In summary, disk blocks are the fundamental units that the filesystem uses to manage and allocate space for files and directories on a storage device.
