tag: #linux

The default Debian installer is competent. It is also opinionated. It makes a dozen choices on your behalf that you would probably make differently if you knew you were making them. The Expert Install is not for elite users. It is for anyone who wants to know what their system actually contains the moment after first boot.

This afternoon the primary Proxmox hypervisor in the homelab refused to boot. Several VMs went offline. Hours of recovery later, every service was back up and no VM data had been lost. This post is the writeup of what failed, what saved the data, and the three hardening layers that have been permanently added so that the next incident in this family does not reach the "blind boot from a serial console" stage.

Sally O'Malley at Red Hat Emerging Tech published tank-os in April 2026, a Fedora bootc image that runs AI agents as rootless Podman workloads. The architecture is small, the disciplines it composes are obvious in retrospect, and it is the cleanest available demonstration of what an agent host should look like in 2026.

A zombie process is already dead. kill minus nine does nothing to it. The fix is always one level up the process tree, because the bug is in the parent that failed to reap its child, never in the child itself.

The Linux kernel has had a written rule about commit hygiene since before the platforms most engineers use today existed. "Separate each logical change into a separate patch." The rule is currently being violated at an industrial scale by everyone using LLM assistants to write code, because the assistants produce sprawling multi-concern diffs by default. The kernel's discipline is the cleanest answer to the resulting mess, and it scales down to any project size.

A binary deleted from disk while the process is still running is not actually gone. The kernel keeps the inode alive as long as the process holds it, and /proc/PID/exe is a real readable handle to it. You can copy a running program out of /proc and reconstruct it on disk byte for byte.

Copy Fail, Dirty Frag, Fragnesia, ssh-keysign-pwn - four Linux kernel root exploits in three weeks. The kernel is fine. The admins are not.

The bash !$ history expansion substitutes the last argument of the previous command which turns destructive operations like rm into a two-step ritual where the first step is always a preview.

eBPF is the most interesting thing to happen to the Linux kernel in the last decade and one of the least understood.