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, such as JSON payload. For Prometheus-based metrics, see the Node Exporter Metrics input plugin.

Configuration parameters

The plugin supports the following configuration parameters:

Key	Description	Default
dev_name	Device name to limit the target (for example, sda). If not set, in_disk gathers information from all of disks and partitions.	all disks
interval_nsec	Polling interval in nanoseconds.	0
interval_sec	Polling interval in seconds.	1
threaded	Indicates whether to run this input in its own thread.	false

Get 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

You can run the plugin from the command line:

fluent-bit -i disk -o stdout

Which returns information like the following:

...
[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:

fluent-bit.yaml

pipeline:
  inputs:
    - name: disk
      tag: disk
      interval_sec: 1
      interval_nsec: 0

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

Total interval (sec) = interval_sec + (interval_nsec / 1000000000)

For example: 1.5s = 1s + 500000000ns