iostat

Report CPU and disk I/O statistics.

low risk

interactive breakdown — edit the command and press Explain
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What it does

iostat (from sysstat package) reports CPU utilization and per-device disk I/O metrics including throughput (MB/s), IOPS, and await (average I/O wait time in ms). The -x flag provides extended per-device statistics essential for storage performance analysis.

Common flags
FlagMeaning
-x --extendedShow extended disk statistics
-d --deviceShow device utilization only
-c --cpuShow CPU statistics only
-h --humanHuman-readable sizes
Examples
iostat -x 1 5Extended disk stats, every second, 5 samples · explain & risk-check →
iostat -xh 2Human-readable extended I/O stats every 2s · explain & risk-check →
iostat -d /dev/sda 1Monitor specific disk every second · explain & risk-check →
Pro tip

In `iostat -x` output, focus on `await` (avg I/O wait ms) and `%util` (device saturation). `await` > 20ms or `%util` > 80% signals a storage bottleneck.

Related
vmstat df iotop
Open the full explainer →More in System & Processes

Reference text is hand-written and may be incomplete — check man iostat for your version. Test destructive commands on a non-production system first.