When a Linux server shows high iowait and becomes unresponsive, this guide walks you through using iostat, iotop, blktrace, fio and bpftrace to pinpoint the offending process, understand the full I/O stack, and apply kernel‑level and filesystem tuning to resolve the bottleneck.
When iowait jumps to 80% and commands stall, this guide walks through the Linux I/O stack, explains key iostat metrics, and shows how to pinpoint offending processes with iotop, then uses blktrace, btt, fio, and bpftrace to diagnose and tune storage performance.
This guide walks you through a step‑by‑step, non‑disruptive workflow for diagnosing high disk I/O on Linux servers using built‑in tools such as vmstat, iostat, iotop, pidstat, lsof and the low‑level tracer blktrace, then shows how to interpret the data, identify common root causes, apply targeted fixes, and verify improvements with fio benchmarks and continuous monitoring.
This guide explains how to install fio on Ubuntu 20.04, configure test environments, run IOPS and latency benchmarks with specific parameters, and interpret key metrics such as bandwidth, IOPS, slat, and clat to evaluate storage performance under high‑load and single‑request scenarios.
This comprehensive guide explains Linux disk I/O fundamentals, compares HDD and SSD characteristics, details file system structures, outlines I/O operation flow, introduces key performance metrics like IOPS, throughput and latency, and provides practical testing tools and optimization techniques for both applications and storage layers.
This guide explains how to install fio, run various disk performance tests—including random and sequential reads/writes and mixed workloads—while avoiding data loss, and shows how to interpret key metrics such as IOPS, bandwidth, and latency.
This article details how a team evaluated and improved etcd cluster write performance on AWS by testing gp2 volume IOPS limits, using etcdctl and fio, upgrading to GP3, and analyzing latency and throughput to identify storage bottlenecks and achieve faster synchronization.
Learn how to use macOS’s built-in dmc utility to artificially throttle disk read/write speeds, configure various HDD/SSD profiles, and verify the impact with fio benchmarks, enabling realistic performance testing on low-speed machines without complex cgroup or Docker setups.
A technical deep‑dive shows how a team managing dozens of Kubernetes clusters diagnosed a write‑ahead‑log bottleneck in etcd, measured IOPS and latency with etcdctl and fio, upgraded gp2 volumes to gp3, and discovered diminishing returns beyond 3000 IOPS while explaining the role of fdatasync in storage performance.
This guide explains how to choose Linux I/O schedulers, generate realistic storage workloads with fio, configure various RAID levels using mdadm and LVM, and monitor performance with tools like top, iostat, iotop, blktrace, and atop, providing practical command examples and best‑practice recommendations.
This article details how upgrading AWS EBS volumes from gp2 to GP3 and adjusting instance types improved etcd cluster write throughput, analyzes IOPS bottlenecks using iostat and fio, and explains why further IOPS gains remain constrained by storage and OS caching.
This article explains Linux disk I/O performance metrics, benchmark methods, observation tools like iostat, pidstat, and iotop, and walks through a practical case of diagnosing and resolving an I/O spike caused by the jbd2 journaling process.
This guide explains how to benchmark a Ceph storage cluster before production by measuring hardware baselines, disk read/write performance, network throughput, and using Ceph's built‑in tools like rados bench, load‑gen, rbd bench‑write, and fio for comprehensive performance testing.
This guide shows how to deploy the Dbench Job on a Kubernetes cluster, run nine 15‑second fio tests against a 1000Gi SSD storage class, and interpret the resulting IOPS, bandwidth, and latency metrics for both random and sequential workloads.
This article explains the various classifications of Linux I/O—including buffered, direct, synchronous, and asynchronous types—describes the kernel’s block layer and I/O scheduler algorithms, and provides practical guidance for measuring disk performance using the FIO tool with example commands and scripts.
This article details a systematic fio benchmark comparing sequential and random I/O performance of RAID‑5 servers equipped with SSDs versus HDDs, revealing that while sequential throughput is similar, SSDs deliver dozens‑fold higher bandwidth and dramatically lower latency for random reads.
This article presents a detailed fio benchmark comparing sequential and random I/O on a 7‑disk RAID5 array, revealing how I/O size, RAID strip size, and caching affect bandwidth, latency, and IOPS, and explains the implications for database transactions, file copying, and B+‑tree indexing.
This article outlines five typical cloud‑host file‑loss scenarios—including tmpfs data loss after reboot, accidental rm commands, and disk damage from fio or dd—explains their causes, and provides practical prevention and recovery recommendations for operations engineers.
This article explains how to evaluate SSD performance by processing raw fio benchmark logs, interpreting bandwidth, IOPS, and latency metrics, converting logs to CSV, visualizing results with charts, and drawing practical conclusions for storage selection and reliability.
This article explains how to evaluate SSD performance by detailing the benchmark environment, required hardware, preferred testing tools like fio, essential disk requirements, common pitfalls, and a comprehensive set of test items and scripts for both raw disks and typical filesystems.
