nftables sets are the single biggest performance lever most firewall configurations never touch. A ruleset with 400 individual ip saddr matches evaluates linearly; the same 400 addresses placed in a…
Read MoreMTU and PMTUD Black Holes: Diagnosing the Stalls That Look Like TLS Failures
Most TLS failures that are not certificate errors are MTU problems wearing a disguise. The TCP handshake completes, the certificate verifies, the first small HTTP response arrives — and then…
Read MoreTLS 1.3 Post-Quantum Hybrid Key Exchange on a VPS: Measuring the CPU and Handshake Cost
OpenSSL 3.5 and BoringSSL now ship the X25519MLKEM768 hybrid group enabled by default, and browsers have started negotiating it. On a VPS, that changes the arithmetic of a TLS handshake:…
Read MoreNVMe Wearout Telemetry on a VPS: Reading SMART Attributes to Predict SSD Failure
An NVMe drive fails in a predictable sequence: endurance is consumed, spare blocks are reallocated, the media error rate climbs, and only then does write latency spike and the device…
Read MoreLowering DNS TTL Before a VPS Cutover: A Measured Rollback-Safe Procedure
A cutover fails in the rollback, not in the switch. The switch is one edit to an A record; the rollback is where you discover a resolver on the other…
Read MoreHugepages and io_uring on a VPS: Measuring Real Throughput Gains
Two kernel features get recommended together in almost every high-throughput tuning guide: transparent hugepages for the page tables, and io_uring for the syscall path. They solve different problems — one…
Read MoreWireGuard Performance Tuning on a VPS: MTU, Multicore and Throughput Measurement
WireGuard is fast by default, but “fast by default” is not the same as “fast on your VPS”. A single-threaded tunnel on a small instance can saturate at a few…
Read Moredm-crypt and LUKS Encryption Overhead on a VPS: Measuring the Real Cost of AES-NI
Encrypting a VPS disk used to mean paying a heavy performance tax. With AES-NI hardware acceleration present, that tax is often under five percent for throughput and near zero for…
Read MoreBenchmarking NVMe I/O Throughput on a KVM VPS with fio and iostat
“NVMe-backed storage” is a marketing line on nearly every VPS product page. Whether the storage on your specific instance actually delivers NVMe-class throughput is something you can measure in about…
Read MoreTuning Nginx for High-Concurrency VPS Workloads: worker_connections and Keepalive Sizing
Nginx is famous for handling enormous concurrency on modest hardware, but the defaults are conservative and the tuning advice online is mostly copy-pasted folklore. The real limits are arithmetic, not…
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