bitesize(8) System Manager's Manual bitesize(8)

# [NAME](#NAME)

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

# [SYNOPSIS](#SYNOPSIS)

**bitesize**

# [DESCRIPTION](#DESCRIPTION)

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

This works by tracing block:block\_rq\_issue and prints a histogram of I/O size.

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

# [REQUIREMENTS](#REQUIREMENTS)

CONFIG\_BPF and bcc.

# [EXAMPLES](#EXAMPLES)

[Count I/O size per process until Ctrl-C is hit:](#Count)

\# **bitesize**

# [FIELDS](#FIELDS)

[Kbtes](#Kbtes)

Size in kilobytes of range

[count](#count)

How many I/O fell into this range

[distribution](#distribution)

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

# [OVERHEAD](#OVERHEAD)

This traces a block I/O tracepoint to update a histogram, which is 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](#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](#OS)

Linux

# [STABILITY](#STABILITY)

Unstable - in development.

# [AUTHOR](#AUTHOR)

Allan McAleavy

# [SEE ALSO](#SEE_ALSO)

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

2016-02-05 USER COMMANDS

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Document: bitesize(8) from bcc 0.37.0-r2 (Chainguard OS)
Source: https://github.com/iovisor/bcc