---
title: ''
description: Telegraf plugin for collecting metrics from Bcache
url: https://docs.influxdata.com/telegraf/v1/input-plugins/bcache/
estimated_tokens: 632
product: Telegraf Enterprise
version: v1
publisher: InfluxData
canonical: https://docs.influxdata.com/telegraf/v1/input-plugins/bcache/
date: '2026-05-21T20:10:18+02:00'
lastmod: '2026-05-21T20:10:18+02:00'
---

==========

* Telegraf v0.2.0+

[Plugin source](https://github.com/influxdata/telegraf/tree/v1.39.1/plugins/inputs/bcache/)[Download configuration](https://raw.githubusercontent.com/influxdata/telegraf/refs/tags/v1.39.1/plugins/inputs/bcache/sample.conf)

# Bcache Input Plugin

This plugin gathers statistics for the [block layer cache](https://docs.kernel.org/admin-guide/bcache.html)from the `stats_total` directory and `dirty_data` file.

**Introduced in:** Telegraf v0.2.0**Tags:** system**OS support:** linux

## Global configuration options

Plugins support additional global and plugin configuration settings for tasks
such as modifying metrics, tags, and fields, creating aliases, and configuring
plugin ordering. See [CONFIGURATION.md](/telegraf/v1/configuration/#plugins) for more details.

## Configuration

```toml
# Read metrics of bcache from stats_total and dirty_data
# This plugin ONLY supports Linux
[[inputs.bcache]]
  ## Bcache sets path
  ## If not specified, then default is:
  bcachePath = "/sys/fs/bcache"

  ## By default, Telegraf gather stats for all bcache devices
  ## Setting devices will restrict the stats to the specified
  ## bcache devices.
  bcacheDevs = ["bcache0"]
```

## Metrics

Tags:

* `backing_dev` device backed by the cache
* `bcache_dev` device used for caching

Fields:

* `dirty_data`: Amount of dirty data for this backing device in the cache.
  Continuously updated unlike the cache set’s version, but may be slightly off
* `bypassed`: Amount of IO (both reads and writes) that has bypassed the cache
* `cache_bypass_hits`: Hits for IO that is intended to skip the cache
* `cache_bypass_misses`: Misses for IO that is intended to skip the cache
* `cache_hits`: Hits per individual IO as seen by bcache sees them; a
  partial hit is counted as a miss.
* `cache_misses`: Misses per individual IO as seen by bcache sees them; a
  partial hit is counted as a miss.
* `cache_hit_ratio`: Hit to miss ratio
* `cache_miss_collisions`: Instances where data was going to be inserted into
  cache from a miss, but raced with a write and data was already present
  (usually zero since the synchronization for cache misses was rewritten)
* `cache_readaheads`: Count of times readahead occurred.

## Example Output

```text
bcache,backing_dev="md10",bcache_dev="bcache0" dirty_data=11639194i,bypassed=5167704440832i,cache_bypass_hits=146270986i,cache_bypass_misses=0i,cache_hit_ratio=90i,cache_hits=511941651i,cache_miss_collisions=157678i,cache_misses=50647396i,cache_readaheads=0i
```