IOSTAT(1) Linux User's Manual IOSTAT(1) (NAME) iostat - (CPU) / (SYNOPSIS) iostat [ -c ] [ -d ] [ -h ] [ -k | -m ] [ -N ] [ -s ] [ -t ] [ -U ] [ -V ] [ -x ] [ -y ] [ -z ] [ --compact ] [ --dec={ 0 | 1 | 2 } ] [ { -f | +f } directory ] [ -j { ID | LABEL | PATH | UUID | ... } ] [ -o JSON ] [ [ -H ] -g group_name ] [ --human ] [ --pretty ] [ -p [ device[,...] | ALL ] ] [ device [...] | ALL ] [ interval [ count ] ] (DESCRIPTION) iostat / . iostat / . iostat () -y ( ). . iostat . CPU CPU . CPU . . interval . count interval . count interval . interval count iostat . (REPORTS) iostat : (CPU Utilization report) (Device Utilization report). (CPU Utilization Report) iostat . CPU . : %user () . %nice nice . %system (/) . %iowait / . %steal . %idle / . (Device Utilization Report) iostat . . . . ALL . POSIXLY_CORRECT . ( -x -s -k -m) : Device: ( ) /dev . tps . / (I/O) . / . . Blk_read/s (kB_read/s, MB_read/s) ( ) . . Blk_wrtn/s (kB_wrtn/s, MB_wrtn/s) ( ) . Blk_dscd/s (kB_dscd/s, MB_dscd/s) (discard) ( ) . Blk_w+d/s (kB_w+d/s, MB_w+d/s) ( ) . Blk_read (kB_read, MB_read) ( ) . Blk_wrtn (kB_wrtn, MB_wrtn) ( ) . Blk_dscd (kB_dscd, MB_dscd) ( ) . Blk_w+d (kB_w+d, MB_w+d) ( ) . r/s ( ). w/s ( ). d/s (discard) ( ). f/s (flush / ) ( ). . . . sec/s (kB/s, MB/s) ( ) . rsec/s (rkB/s, rMB/s) ( ) . wsec/s (wkB/s, wMB/s) ( ) . dsec/s (dkB/s, dMB/s) ( ) . rqm/s / . rrqm/s . wrqm/s . drqm/s . %rrqm . %wrqm . %drqm . areq-sz ( ) / . : avgrq-sz . rareq-sz ( ) . wareq-sz ( ) . dareq-sz ( ) . await ( ) / . . r_await ( ) . . w_await ( ) . . d_await ( ) . . f_await ( ) . . : . aqu-sz . : avgqu-sz . %util / ( ). . RAID SSD . (OPTIONS) -c (CPU). --compact . -d . --dec={ 0 | 1 | 2 } ( ). -f directory +f directory iostat . -f iostat +f . directory (userspace) . : - "diskstats" "/proc" - "/sys" . directory iostat : directory/block/device/stat directory/block/device/partition/stat partition directory/dev/block/ : directory/dev/block/major:minor --> ../../block/device/partition -g group_name { device [...] | ALL } . iostat group_name . ALL . -H -g . -h --human --pretty . --human ( 1.0k 1.2M ). ( ...) . -j { ID | LABEL | PATH | UUID | ... } [ device [...] | ALL ] . ID LABEL PATH UUID . /dev/disk . . --pretty . -k . -m . -N (device mapper) . LVM2 . -o JSON JSON (JavaScript Object Notation). JSON . -p [ { device[,...] | ALL } ] . . ALL . -j . --pretty . . ( --compact ). -s () . -t . S_TIME_FORMAT ( ) -U . -U (UTC - ) (Epoch). -V . -x (extended statistics). -y . -z iostat . (ENVIRONMENT) iostat : POSIXLY_CORRECT . S_COLORS . . never always auto ( ). ( ) . S_COLORS_SGR . I=32;22:N=34;1:W=35;1:X=31;1:Z=34;22 . : I= SGR (Select Graphic Rendition) . N= SGR . W= ( M=) SGR ( ). X= ( H=) SGR ( ). Z= SGR . S_TIME_FORMAT ISO (locale) . iostat ISO 8601 (YYYY-MM-DD) . -t ISO 8601 . (EXAMPLES) iostat . iostat -d 2 . iostat -d 2 6 . iostat -x sda sdb 2 6 sda sdb. iostat -p sda 2 6 sda (sda1 ). (BUGS) /proc iostat (mount) . 2.6.x . iostat (kB) (MB)... (kiB) (MiB)... . . (FILES) /proc/stat . /proc/uptime . /proc/diskstats . /sys . /proc/self/mountstats . /dev/disk . (AUTHOR) Sebastien Godard (sysstat orange.fr) (SEE ALSO) sar(1), pidstat(1), mpstat(1), vmstat(8), tapestat(1), nfsiostat(1), cifsiostat(1) https://github.com/sysstat/sysstat https://sysstat.github.io Linux JULY 2025 IOSTAT(1)