Tag: kernel

PREEMPT_RT hit Linux mainline in 2024. Here's what real-time actually means, when you need it, and when it'll just slow you down.

Linux PSI (Pressure Stall Information) exposes real CPU, memory, and IO stall percentages, here's why it beats load average for monitoring.

io_uring slashes syscall overhead vs epoll and AIO. Covers the submission/completion queue model, liburing examples, security caveats, and when to skip it.

Containers are just namespaces and cgroups in a trench coat. Build one yourself with unshare and nsenter, no Docker required. Here's what actually happens.

CVE-2026-31431 (copy.fail) lets any local user become root on virtually every Linux system since 2017. Here's what it is, why it matters, and how to fix it.

Linux ships with conservative kernel defaults. These sysctl settings tune your server for networking, memory, and file I/O, with explanations, not just paste-and-pray values.

A kernel upgrade halved one team's PostgreSQL throughput. The fix was kernel tuning: huge pages, THP, swappiness, I/O scheduler. Here's what matters and why.

Linux suspend vs hibernate explained: sleep states, swap setup, initramfs resume hook, wake-on-LAN, lid close behavior, and fixing common hibernate failures on modern Linux systems.

Your Linux box has hundreds of kernel knobs in /proc/sys that nobody ever touches. Most do not matter. Here are the handful that actually improve a Docker host.

Kernel live patching applies CVE fixes to a running kernel with no reboot, using kpatch or Canonical Livepatch. Setup for Ubuntu and RHEL, plus what it can't fix.

Tmpfs vs ramfs on Linux: mount RAM-backed filesystems for blazing-fast temp storage. Covers fstab, Docker tmpfs mounts, CI/CD use cases, and the key differences.

Linux entropy pools decide how fast a box generates SSH keys and TLS certs. What haveged, virtio-rng, and hardware RNG fix on a freshly booted VM.