This article explains how Linux file systems represent file size versus actual disk usage, demonstrates the difference between Size and Blocks using du and stat, describes inode and multi‑level block indexing, and shows why copying a sparse 100 GB file with cp finishes in a fraction of a second.
The article explains why a 100 GB file can be copied in under a second by examining the difference between logical file size and physical block usage, demonstrating sparse file behavior, inode structure, direct and indirect block indexing, and how these mechanisms affect copy performance on Linux.
This article explains why the Linux cp command appears to copy a 100 GB file in less than a second by exploring sparse files, the distinction between file size and allocated blocks, inode structure, multi‑level block indexing, and how these concepts enable fast copying of seemingly huge files.
The article explains how a Linux file can appear to be 100 GB yet copy in under a second because the file system uses inodes, direct and indirect block pointers, and sparse allocation, separating logical size from actual physical storage.
A colleague was amazed when the cp command copied a 100 GB file in less than a second, prompting an investigation that reveals the difference between logical file size and physical block usage, the role of inodes, direct and indirect block indexing, and how sparse files make such copies appear instantaneous.
The article explains how Linux file systems use inodes and multi‑level block indexing to separate a file's logical size from its physical storage, illustrating why copying a seemingly huge file with the cp command can complete instantly when the file is sparse.
