DBMS

A memo for Linux I/O and Filesystem

November 27, 2025
DBMS

A memo for Linux I/O and Filesystem, collected from AI chat threads

This memo is an extended memo for this post, consolidates knowledge about:

  • VFS & Filesystem Delegation
  • File descriptors & open file table
  • stdio / unbuffered / direct I/O
  • Page Cache, Writeback
  • fsync vs fdatasync (accurate across ext4, XFS, Btrfs, ZFS)
  • open flags
  • Pipes, dup2
  • fork, clone, exec
  • splice / zero-copy design

Designed as a reference entry for systems and storage engine development.

...