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This article explains the purpose, design, and internal data structures of ext4 extents, describes how the B+‑tree indexes extents for efficient mapping of logical to physical blocks, and compares ext4’s extent mechanism with older file‑system addressing methods and other modern file systems.
This article explains the object‑oriented design of the Linux VFS, details the four core VFS structures, shows how ext4 is registered and mounted via register_filesystem and ext4_mount, and walks through the six‑step ext4_fill_super process for initializing superblocks and related metadata.
This article explains how the ext4 file system organizes data using inodes, direct and indirect blocks, extents, and directory indexing, detailing the structures, code definitions, and performance implications for both small and large files.
This article explains the physical and logical operation of mechanical hard drives and solid‑state drives, details the Ext4 filesystem structures such as superblocks, inodes, block groups, flexible and meta block groups, and outlines allocation strategies and link types.
The article explains how directories consume inodes and filesystem blocks, how this consumption grows with many files or long filenames, and why the ls command can become sluggish, offering practical tips to mitigate the performance impact.
This guide explains Linux file timestamps (ATime, MTime, CTime), why creation time is missing on older filesystems, and provides step‑by‑step methods—including using stat, debugfs, and a custom shell script—to obtain a file’s creation (crtime) timestamp on ext4 systems.
This article explores the evolution, architecture, and key features of Linux EXT filesystems—including Minix origins, EXT2, EXT3, and EXT4—detailing metadata structures, inode handling, fragmentation mitigation, journaling, and practical upgrade and maintenance considerations.
This article examines a Linux 3.10 kernel soft‑lockup bug where the ext4 extent‑status LRU spin‑lock is held for over 20 seconds under memory pressure, explains the ext4 delayed‑allocation mechanism, block lookup process, extent‑status cache shrinkage, and presents the community's mitigation approach.
This article explains what happens inside the Linux kernel when the rm command deletes a file on an ext4 filesystem, analyzes the relevant VFS and ext4 source code, and demonstrates how large‑file deletions can degrade I/O performance of other applications.
This guide explains how to manage large Linux disks by using GPT partition tables, choosing XFS or EXT4 filesystems, performing partitioning with parted, formatting with appropriate mkfs commands, handling e2fsprogs version requirements, and considerations for lazy init and snapshot impacts.