bitesize man page

bitesize — Summarize block device I/O size as a histogram — Linux eBPF/bcc.

Synopsis

bitesize

Description

Show I/O distribution for requested block sizes, by process name.

This works by tracing block I/O kernel functions using dynamic tracing and prints a historgram of I/O size.

Since this uses BPF, only the root user can use this tool.

Requirements

CONFIG_BPF and bcc.

Examples

Count I/O size per process until Ctrl-C is hit:

# bitesize

Fields

Kbtes

Size in kilobytes of range

count

How many I/O fell into this range

distribution

An ASCII bar chart to visualize the distribution (count column)

Overhead

This traces kernel block I/O functions to update a histgroam, which are asynchronously copied to user-space. This method is very efficient, and  the overhead for most storage I/O rates (< 10k IOPS) should be negligible.  If you have a higher IOPS storage environment, test and quantify the overhead  before use.

Source

This is from bcc.

https://github.com/iovisor/bcc

Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.

OS

Linux

Stability

Unstable - in development.

Author

Allan McAleavy

See Also

https://github.com/brendangregg/systemtap-lwtools/blob/master/disk/bitesize-nd.stp

Info

2016-02-05 USER COMMANDS