{"id":464,"date":"2026-10-14T15:01:33","date_gmt":"2026-10-14T15:01:33","guid":{"rendered":"http:\/\/www.scmgalaxy.com\/tutorials\/2015\/12\/12\/20-iostat-commands-examples-in-linux-unix\/"},"modified":"2026-10-14T15:01:33","modified_gmt":"2026-10-14T15:01:33","slug":"20-iostat-commands-examples-in-linux-unix","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/20-iostat-commands-examples-in-linux-unix\/","title":{"rendered":"iostat Command Guide for Linux: 20 Practical Examples for CPU and Disk I\/O Troubleshooting"},"content":{"rendered":"\n

The iostat<\/code> command helps Linux and Unix operators quickly understand CPU usage<\/strong> and disk I\/O behavior<\/strong>. If you troubleshoot slow applications, storage latency, or noisy hosts, this guide gives you practical commands and a repeatable workflow.<\/p>\n\n\n\n

Originally published on 2015-12-12; fully revised and updated.<\/em><\/p>\n\n\n

\n
\"iostat<\/figure>\n<\/div>\n\n\n

What iostat reports<\/h2>\n\n\n\n

iostat<\/code> (part of the sysstat<\/code> package on Linux) reports two main categories:<\/p>\n\n\n\n

  • CPU statistics<\/strong> (overall CPU state percentages such as user, system, idle, and iowait).<\/li>
  • Device I\/O statistics<\/strong> (throughput, operation rates, queueing, and utilization for block devices and partitions).<\/li><\/ul>\n\n\n\n

    Linux builds usually read from kernel-provided interfaces such as \/proc\/stat<\/code>, \/proc\/diskstats<\/code>, \/proc\/partitions<\/code> (older kernels), and \/sys<\/code>.<\/p>\n\n\n\n

    iostat vs related system tools<\/h2>\n\n\n\n
    Tool<\/th>Best for<\/th>Typical use<\/th><\/tr><\/thead>
    iostat<\/code><\/td>Disk and CPU I\/O view<\/td>Find busy disks, high await, high device utilization<\/td><\/tr>
    vmstat<\/code><\/td>Memory and scheduler behavior<\/td>Check run queue, swap activity, system pressure<\/td><\/tr>
    mpstat<\/code><\/td>Per-CPU analysis<\/td>Detect imbalanced CPU load and per-core hotspots<\/td><\/tr>
    pidstat<\/code><\/td>Per-process resource usage<\/td>Map host-level pressure to specific processes<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    Install and verify iostat on Linux<\/h2>\n\n\n\n

    On most Linux distributions, iostat<\/code> is shipped by sysstat<\/code>. You usually do not need a root shell for reading stats, but package installation needs elevated privileges.<\/p>\n\n\n

    # Check whether iostat is already installed<\/span>\nwhich iostat\n\n# Show version (sysstat version)<\/span>\niostat -V\n\n# RHEL\/CentOS\/Amazon Linux<\/span>\nsudo yum install -y sysstat\n\n# Fedora and newer RHEL-family systems<\/span>\nsudo dnf install -y sysstat\n\n# Debian\/Ubuntu<\/span>\nsudo apt-get update && sudo apt-get install -y sysstat\n\n# RPM-based verification<\/span>\nrpm -qa | grep -i sysstat<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
    Workflow: triage storage bottlenecks with iostat<\/h2>\n\n\n\n
    \nflowchart TD\n    A[Alert high app latency] --> B[Run iostat -x 1 5]\n    B --> C{High await or high util}\n    C -- no --> D[Check CPU memory network with mpstat vmstat]\n    C -- yes --> E[Identify busiest device]\n    E --> F[Correlate with process tools]\n    F --> G[Apply fix tune rebalance or scale]\n    G --> H[Re-run iostat and validate]\n<\/pre>\n\n\n\n
    20 practical iostat commands (Linux sysstat)<\/h2>\n\n\n\n
    The following examples are Linux-focused. Option availability can vary by sysstat<\/code> version and by Unix flavor, so confirm with man iostat<\/code> on your host.<\/p>\n\n\n\n
    #<\/th>Command<\/th>Purpose<\/th><\/tr><\/thead>
    1<\/td>iostat<\/code><\/td>Default CPU and device report (first report is since boot).<\/td><\/tr>
    2<\/td>iostat -c<\/code><\/td>CPU statistics only.<\/td><\/tr>
    3<\/td>iostat -d<\/code><\/td>Device statistics only.<\/td><\/tr>
    4<\/td>iostat -x<\/code><\/td>Extended device statistics.<\/td><\/tr>
    5<\/td>iostat -t<\/code><\/td>Add timestamp to each report.<\/td><\/tr>
    6<\/td>iostat -m<\/code><\/td>Show throughput in MB\/s units.<\/td><\/tr>
    7<\/td>iostat -k<\/code><\/td>Show throughput in kB\/s units.<\/td><\/tr>
    8<\/td>iostat 2<\/code><\/td>Refresh every 2 seconds until interrupted.<\/td><\/tr>
    9<\/td>iostat 2 3<\/code><\/td>Refresh every 2 seconds, 3 reports total.<\/td><\/tr>
    10<\/td>iostat -d 1 5<\/code><\/td>Device-only report every second, 5 times.<\/td><\/tr>
    11<\/td>iostat -x 1 5<\/code><\/td>Extended report every second, 5 times.<\/td><\/tr>
    12<\/td>iostat -p sda<\/code><\/td>Show device and partition stats for one device.<\/td><\/tr>
    13<\/td>iostat -p ALL<\/code><\/td>Show all devices and partitions.<\/td><\/tr>
    14<\/td>iostat -x sda 1 5<\/code><\/td>Extended stats focused on one device over time.<\/td><\/tr>
    15<\/td>iostat -N<\/code><\/td>Display device-mapper or LVM-friendly names (if supported).<\/td><\/tr>
    16<\/td>iostat -c -d<\/code><\/td>Explicitly request CPU and device sections.<\/td><\/tr>
    17<\/td>iostat -t -x -m 2 10<\/code><\/td>Timestamped extended report in MB\/s every 2 seconds.<\/td><\/tr>
    18<\/td>iostat -y 1 5<\/code><\/td>Skip first boot-average report (if supported).<\/td><\/tr>
    19<\/td>iostat -z 1 5<\/code><\/td>Hide idle devices in output (if supported).<\/td><\/tr>
    20<\/td>iostat -V<\/code><\/td>Show iostat\/sysstat version information.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n
    # Example live triage session<\/span>\niostat -x -m 1<\/span> 10<\/span>\niostat -p ALL 1<\/span> 5<\/span>\nmpstat 1<\/span> 5<\/span>\nvmstat 1<\/span> 5<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
    How to read key extended fields<\/h2>\n\n\n\n
    Field (common names)<\/th>What it indicates<\/th>Troubleshooting hint<\/th><\/tr><\/thead>
    r\/s<\/code>, w\/s<\/code><\/td>Read\/write operations per second<\/td>Useful for understanding IOPS demand pattern.<\/td><\/tr>
    rkB\/s<\/code>, wkB\/s<\/code><\/td>Read\/write throughput<\/td>Compare bandwidth demand across devices.<\/td><\/tr>
    await<\/code><\/td>Average time for I\/O completion<\/td>Rising await often means latency pressure.<\/td><\/tr>
    avgqu-sz<\/code> or aqu-sz<\/code><\/td>Average queue depth<\/td>Growing queue with rising await suggests contention.<\/td><\/tr>
    %util<\/code><\/td>Device busy time percentage<\/td>Sustained high values can indicate saturation.<\/td><\/tr>
    CPU %iowait<\/code><\/td>CPU time waiting on I\/O<\/td>High iowait with high disk latency points to storage bottlenecks.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    Compatibility notes across Linux and Unix variants<\/h2>\n\n\n\n
    Older tutorials often mix Linux and non-Linux iostat<\/code> options. For example, some Unix variants document flags not present in current Linux sysstat<\/code> builds. Always validate command syntax with the local man page before automating.<\/p>\n\n\n\n
    Best practices<\/h2>\n\n\n\n
    • Capture repeated samples (interval count<\/code>) instead of relying on one snapshot.<\/li>
    • Use -x<\/code> during incidents to see latency and queue behavior, not just throughput.<\/li>
    • Correlate host-level metrics with process-level tools (pidstat<\/code>, iotop<\/code>) before changing configuration.<\/li>
    • Record timestamps (-t<\/code>) when comparing with application and database logs.<\/li>
    • Treat field names as version-dependent; confirm on each distribution baseline.<\/li><\/ul>\n","protected":false},"excerpt":{"rendered":"
      Learn how to use iostat to monitor CPU and storage performance on Linux systems. This revised guide covers installation, 20 practical commands, metric interpretation, and a troubleshooting workflow.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_joinchat":[],"footnotes":""},"categories":[4957],"tags":[378,632,1283,1284,1285,1288,1287,460,1286,169],"class_list":["post-464","post","type-post","status-publish","format-standard","hentry","category-linux","tag-commands","tag-examples","tag-iostat","tag-iostat-command","tag-iostat-command-examples","tag-iostat-command-line","tag-iostat-commands-tutorials","tag-linux","tag-linux-iostat-command","tag-unix"],"_links":{"self":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/464","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/comments?post=464"}],"version-history":[{"count":5,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/464\/revisions"}],"predecessor-version":[{"id":79348,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/464\/revisions\/79348"}],"wp:attachment":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/media?parent=464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/categories?post=464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/tags?post=464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}