Writing
Notes on networking, the Linux data path, firmware, and running things myself. Mostly the write-ups I wanted to exist when I was solving the problem.
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- A nightly backup filled my Proxmox node and froze the cluster filesystem
A nightly backup filled pve1's ZFS pool, froze /etc/pve and paused five VMs, including my firewall. How I got it back without a reboot, and why it happened.
- Building xdp-bfdseries · 10 parts
How I built a BFD engine that runs in XDP, from why software BFD flaps under load to running it on real hardware and under attack. Every timing and flap number comes from a packet capture.
- Fixing FRR’s BFD daemonseries · 3 posts
Bugs I found and fixed in FRR’s bfdd, mostly while using it with xdp-bfd. Sixteen fixes are merged so far. One post covers all of them, and two of them have longer write-ups.
- Interviewing with Jane Street for a Linux Engineer role
Interviewing with Jane Street for a Linux Engineer role: the basics I made sure of, the deeper Linux work I do, and how it went.
- Fixing my slow offsite backups over WireGuard
My offsite backups had been failing silently for 23 days. Fixing that showed they were also crawling at 16 Mbps over a 1 Gbps tunnel, and the cause turned out to be 0.033% packet loss and TCP cubic.
- How my homelab is set up
Two Proxmox nodes on shared iSCSI storage, a firewall that runs as one of its own guests, one reverse proxy in front of everything, DNS split for inside and outside, and the monitoring that watches it all.
- Turning off JWT auth for my VPN in nginx
I wanted my self-hosted services to skip the login when I'm on my VPN. The JWT module's on/off setting couldn't take a variable, so I added that, and my first version turned auth on for every site.
- Proxmox Disks page failing on a USB SSD
The Disks page in Proxmox kept failing with a communication error when I plugged in an SSD over USB. It came down to a smartctl call that took two minutes and had no timeout.