The kernel primitives, init systems, and tooling behind the world's most-deployed OS.
How fanotify groups mark filesystems, pause opens for an allow-or-deny response, expose queue overflow, and fail open when a policy daemon disappears.
How Linux builds, configures, clones, changes, and attaches mounts through file descriptors, with clearer lifetimes and fewer path-based races.
How openat2 applies explicit path-resolution policy, how its flags differ, and why safe file use still requires directory FDs, validation, and testing.
A precise look at how fs-verity authenticates read-only files, verifies page-cache reads, exposes stable digests, and differs from dm-verity.
How Linux PID file descriptors provide stable process identity for signaling, polling, waiting, and descriptor duplication without PID reuse races.
A storage-accurate explanation of Btrfs extents, subvolumes, snapshots, reflinks, checksums, free-space behavior, consistency, and backup boundaries.
A recovery-first Linux boot workflow for root-device failures covering identifiers, storage drivers, LUKS, LVM, Btrfs, regenerated initramfs, and rollback.
A forensic workflow for Linux inotify exhaustion: identify watch owners, distinguish instances and queue overflow, reduce scope, size limits, and retest.
A safe nmcli workflow for connection profiles, static addressing, DNS, routes, staged activation, rollback, and proof that settings survive reboot.
A practical systemd credentials workflow using LoadCredential, encrypted credentials, service access, rotation, permissions, and failure-safe verification.