Sysadmin on 5ok — sysadmin, devops, hosting

Hosting for an e-shop doing 40,000 orders a month

Wed, 20 May 2026 00:00:00 +0000

The problem

An e-shop built on a custom PHP application ran on managed hosting that fell over during every campaign. Average TTFB 1.8 s, over 6 s at peak. The hosting provider’s answer was that they were “exceeding plan limits”.

What we did

We built dedicated infrastructure across three machines:

App server — Nginx + PHP-FPM, pool settings tuned to the real load profile.
DB server — PostgreSQL with a replica, shared_buffers and work_mem sized to the dataset rather than left at defaults.
Cache layer — Varnish in front of the application for anonymous requests, Redis for sessions and application cache.

The migration ran over a weekend with a 12-minute window for the DNS switch and final database sync.

Bare-metal to Proxmox with no downtime

Mon, 11 May 2026 00:00:00 +0000

The client had four physical servers, one application each. A classic 2015–2018 setup: one server = one service, no virtualisation, no backups beyond rsync to a NAS.

The brief: get it onto Proxmox, gain snapshots and live migration, and keep downtime under a few minutes per service.

The plan

The approach we use almost every time:

Build a new Proxmox cluster alongside (three nodes, Ceph pool).
For each service create a VM and deploy from configuration management — not by cloning the old disk.
Run both instances in parallel, synchronise data one-way.
Switch DNS / load balancer, watch, keep the old instance on standby for a week.

Point 2 matters. Cloning a physical disk into a VM (P2V) is fast, but it carries ten years of sediment with it — old packages, manual /etc edits nobody documented. If you have Ansible, rebuild instead.

Remote monitoring network for a water utility

Thu, 12 Mar 2026 00:00:00 +0000

The brief

Sixty pumping stations and reservoirs scattered across a region, each with a PLC nobody sees until something breaks. The goal: get PLC data into the control room and have real-time visibility.

The solution

We deployed a Teltonika TRB245 at each site — an LTE gateway with RS485 that:

Reads registers from the PLC over Modbus RTU.
Publishes them via MQTT to a central broker.
Maintains a permanent WireGuard tunnel back to HQ for remote PLC access.

Centrally: Mosquitto → Telegraf → Prometheus → Grafana. Alerts reach dispatch via email and an SMS gateway.