---
name: "bitesize-bpfcc"
section: "8"
platform: "linux"
package: "bpfcc-tools"
version: "0.31.0+ds-7"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/bitesize-bpfcc"
---

# bitesize-bpfcc(8)

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

## NAME

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:block\_rq\_issue and prints a histogram 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 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

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