ioping man page

ioping — simple disk I/O latency monitoring tool


ioping .

ioping -c 10 -s 1M /tmp

ioping -R /dev/sda

ioping -RL /dev/sda


ioping directory|file|device
ioping -h | -v


This tool generates various I/O patterns and lets you monitor I/O speed and latency in real time.


-c count

Stop after count requests.

-i interval

Set time between requests to interval (1s).

-l speed

Set speed limit in bytes per second. Set interval to request-size / speed.

-t time

Minimal valid request time (0us). Too fast requests are ignored in statistics.

-T time

Maximum valid request time. Too slow requests are ignored in statistics.

-s size

Request size (4k).

-S wsize

Working set size (1m for directory, whole size for file or device).

-o offset

Starting offset in the file/device (0).

-w deadline

Stop after deadline time passed.

-p period

Print raw statistics for every period requests (see format below).

-P period

Print raw statistics for every period in time.


Use asynchronous I/O (syscalls io_submit(2), io_submit(2), etc).


Batch mode. Be quiet and print final statistics in raw format.


Use cached I/O. Suppress cache invalidation via posix_fadvise(2)) before read and fdatasync(2) after each write.


Use direct I/O (see O_DIRECT in open(2)).


Use sequential operations rather than random. This also sets default request size to 256k (as in -s 256k).


Disk seek rate test. This option suppress human-readable output for each request (as -q), sets default interval to zero (-i 0), stops measurement after 3 seconds (-w 3) and increases default working set size to 64m (-S 64m). Working set (-S) should be increased accordingly if disk has huge cache.


Use writes rather than reads. Safe for directory target. Write I/O gives more reliable results for systems where non-cached reads are not supported or cached at some level. Might be *DANGEROUS* for file/device: it will shred your data. In this case should be repeated tree times (-WWW).


Alternate read and write requests.


Use sync I/O (see O_SYNC in open(2)).


Use data sync I/O (see O_DSYNC in open(2)).


Keep and reuse temporary working file "ioping.tmp" (only for directory target).


Suppress periodical human-readable output.


Display help message and exit.


Display version and exit.

Argument suffixes

For options that expect time argument (-i, -P and -w), default is seconds, unless you specify one of the following suffixes (case-insensitive):


microseconds (a millionth of a second, 1 / 1 000 000)


milliseconds (a thousandth of a second, 1 / 1 000)







For options that expect "size" argument (-s, -S and -o), default is bytes, unless you specify one of the following suffixes (case-insensitive):


disk sectors (a sector is always 512).


kilobytes (1 024 bytes)


memory pages (a page is always 4KiB).


megabytes (1 048 576 bytes)


gigabytes (1 073 741 824 bytes)


terabytes (1 099 511 627 776 bytes)

For options that expect "number" argument (-p and -c) you can optionally specify one of the following suffixes (case-insensitive):


kilo (thousands, 1 000)


mega (millions, 1 000 000)


giga (billions, 1 000 000 000)


tera (trillions, 1 000 000 000 000)

Exit Status

Returns 0 upon success. The following error codes are defined:


Invalid usage (error in arguments).


Error during preparation stage.


Error during runtime.

Raw Statistics

ioping -p 100 -c 200 -i 0 -q .
100 26694 3746 15344272 188 267 1923 228 100 26694
100 24165 4138 16950134 190 242 2348 214 100 24165
(1) (2)   (3)  (4)      (5) (6) (7)  (8) (9) (10)

(1) count of requests in statistics
(2) running time         (usec)
(3) requests per second  (iops)
(4) transfer speed       (bytes/sec)
(5) minimal request time (usec)
(6) average request time (usec)
(7) maximum request time (usec)
(8) request time standard deviation (usec)
(9) total requests       (including too slow and too fast)
(10) total running time  (usec)


ioping .

Show disk I/O latency using the default values and the current directory, until interrupted. This command prepares temporary (unlinked/hidden) working file and reads random chunks from it using non-cached read requests.

ioping -c 10 -s 1M /tmp

Measure latency on /tmp using 10 requests of 1 megabyte each.

ioping -R /dev/sda

Measure disk seek rate.

ioping -RL /dev/sda

Measure disk sequential speed.

ioping -RLB . | awk '{print $4}'

Get disk sequential speed in bytes per second.

See Also

iostat(1), dd(1), fio(1), dbench(1), fsstress, xfstests, hdparm(8), badblocks(8),



This program was written by Konstantin Khlebnikov
Man-page was written by Kir Kolyshkin


Oct 2014 User Commands