Posts

All the articles I've posted.

• It Is Always DNS. This Time It Was Hiding in the Defaults.

  16 Sep, 2025

  CoreDNS CPU was pegged and name resolution failed at random across the cluster. Nothing in the app changed. The load came from a default nobody chose, quietly turning one lookup into five.

• Hardening and Tuning a Shared Hosting Linux Box

  19 Aug, 2025

  A deep how-to on locking down and tuning a Linux server that runs many tenants on one box, kernel semaphores and all

• Diskless Workstations With PXE and iSCSI

  15 Jul, 2025

  A retrospective on running staff workstations with no local disk booted over PXE with home directories on highly available iSCSI storage

• The Day We Stopped Trusting a Flat Datacenter Network

  17 Jun, 2025

  How we rebuilt a Brazilian hosting datacenter from a flat unmanaged network into a segmented one and what that actually changed