disk-io-metrics.md

Disk I/O Metrics

The disk input plugin, gathers the information about the disk throughput of the running system every certain interval of time and reports them.

The Disk I/O metrics plugin creates metrics that are log-based (I.e. JSON payload). If you are looking for Prometheus-based metrics please see the Node Exporter Metrics input plugin.

Configuration Parameters

The plugin supports the following configuration parameters:

Key	Description	Default
Interval_Sec	Polling interval (seconds).	1
Interval_NSec	Polling interval (nanosecond).	0
Dev_Name	Device name to limit the target. (e.g. sda). If not set, in_disk gathers information from all of disks and partitions.	all disks

Getting Started

In order to get disk usage from your system, you can run the plugin from the command line or through the configuration file:

Command Line

$ fluent-bit -i disk -o stdout
Fluent Bit v1.x.x
* Copyright (C) 2019-2020 The Fluent Bit Authors
* Copyright (C) 2015-2018 Treasure Data
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

[2017/01/28 16:58:16] [ info] [engine] started
[0] disk.0: [1485590297, {"read_size"=>0, "write_size"=>0}]
[1] disk.0: [1485590298, {"read_size"=>0, "write_size"=>0}]
[2] disk.0: [1485590299, {"read_size"=>0, "write_size"=>0}]
[3] disk.0: [1485590300, {"read_size"=>0, "write_size"=>11997184}]

Configuration File

In your main configuration file append the following Input & Output sections:

{% tabs %} {% tab title="fluent-bit.conf" %}

[INPUT]
    Name          disk
    Tag           disk
    Interval_Sec  1
    Interval_NSec 0
[OUTPUT]
    Name   stdout
    Match  *

{% endtab %}

{% tab title="fluent-bit.yaml" %}

pipeline:
    inputs:
        - name: disk
          tag: disk
          interval_sec: 1
          interval_nsec: 0
    outputs:
        - name: stdout
          match: '*'

{% endtab %} {% endtabs %}

Note: Total interval (sec) = Interval_Sec + (Interval_Nsec / 1000000000).

e.g. 1.5s = 1s + 500000000ns