ext2
also: Second Extended Filesystem, ext2fs
ext2 is a classic Linux filesystem that stores files in a hierarchical structure using inodes and data blocks. It was the standard filesystem for Linux systems throughout the 1990s before being superseded by ext3 and ext4.
ext2 (second extended filesystem) manages how data is organized and stored on disk. It uses inodes to track file metadata (permissions, ownership, timestamps) and data blocks to store actual file contents. The filesystem is divided into fixed-size block groups for efficient management.
You might format a partition with ext2 using: mkfs.ext2 /dev/sda1. The filesystem supports files up to 2 TB and partitions up to 32 TB, with typical block sizes of 1024, 2048, or 4096 bytes.
ext2 lacks journaling, meaning if the system crashes during a write operation, the filesystem must be checked and repaired with fsck. This limitation led to the development of ext3 (which added journaling) and ext4 (which added modern features like extents). ext2 is rarely used for active systems today but remains useful for USB drives and embedded systems where journaling overhead is unnecessary.