filesystems.md

filesystems

Monitor Type: filesystems (Source)

Accepts Endpoints: No

Multiple Instances Allowed: Yes

Overview

This monitor reports metrics about free disk space on mounted devices.

On Linux hosts, this monitor relies on the /proc filesystem. If the underlying host's /proc file system is mounted somewhere other than /proc please specify the path using the top level configuration procPath.

procPath: /hostfs/proc
monitors:
 - type: filesystems
   hostFSPath: /hostfs

Migrating from collectd/df

The collectd/df monitor is being deprecated in favor of the filesystems monitor. While the collectd/df monitor will still be available in 5.0, it is recommended that you switch to the filesystems monitor soon after upgrading. There are a few incompatibilities to be aware of between the two monitors:

• collectd/df used a dimension called plugin_instance to identify the mount point or device of the filesystem. This dimension is completely removed in the filesystems monitor and replaced by the mountpoint and device dimensions. You no longer have to select between the two (the reportByDevice option on collectd/df) as both are always reported.

• The mountpoints in the plugin_instance dimension of collectd/df were reported with - instead of the more conventional / separated path segments. The filesystems monitor always reports mountpoints in the mountpoint dimension and uses the conventional / separator.

• The collectd/df plugin set a dimension plugin: df on all datapoints, but filesystems has no such comparable dimension.

Configuration

To activate this monitor in the Smart Agent, add the following to your agent config:

monitors:  # All monitor config goes under this key
 - type: filesystems
   ...  # Additional config

For a list of monitor options that are common to all monitors, see Common Configuration.

Config option	Required	Type	Description
hostFSPath	no	string	Path to the root of the host filesystem. Useful when running in a container and the host filesystem is mounted in some subdirectory under /. The disk usage metrics emitted will be based at this path.
fsTypes	no	list of strings	The filesystem types to include/exclude. This is an overridable set. If this is not set, the default value is the set of all non-logical/virtual filesystems on the system. On Linux this list is determined by reading the /proc/filesystems file and choosing the filesystems that do not have the nodev modifier.
mountPoints	no	list of strings	The mount paths to include/exclude. This is an overridable set. NOTE: If you are using the hostFSPath option you should not include the /hostfs/ mount in the filter. If both this and fsTypes is specified, the two filters combine in an AND relationship.
sendModeDimension	no	bool	Set to true to emit the "mode" dimension, which represents whether the mount is "rw" or "ro". (default: false)

Metrics

These are the metrics available for this monitor. Metrics that are categorized as container/host (default) are in bold and italics in the list below.

• df_complex.free (gauge)
  Free disk space in bytes
• df_complex.reserved (gauge)
  Measures disk space in bytes reserved for the super-user on this file system.
• df_complex.used (gauge)
  Used disk space in bytes
• disk.summary_utilization (gauge)
  Percent of disk space utilized on all volumes on this host.
• disk.utilization (gauge)
  Percent of disk used on this volume.

Group inodes

All of the following metrics are part of the inodes metric group. All of the non-default metrics below can be turned on by adding inodes to the monitor config option extraGroups:

• df_inodes.free (gauge)
  (Linux Only) Number of inodes that are free.
• df_inodes.used (gauge)
  (Linux Only) Number of inodes that are used.
• percent_inodes.free (gauge)
  (Linux Only) Free inodes on the file system, expressed as a percentage.
• percent_inodes.used (gauge)
  (Linux Only) Used inodes on the file system, expressed as a percentage.

Group percentage

All of the following metrics are part of the percentage metric group. All of the non-default metrics below can be turned on by adding percentage to the monitor config option extraGroups:

• percent_bytes.free (gauge)
  Free disk space on the file system, expressed as a percentage.
• percent_bytes.reserved (gauge)
  Measures disk space reserved for the super-user as a percentage of total disk space of this file system.
• percent_bytes.used (gauge)
  Used disk space on the file system, expressed as a percentage.

Non-default metrics (version 4.7.0+)

To emit metrics that are not default, you can add those metrics in the generic monitor-level extraMetrics config option. Metrics that are derived from specific configuration options that do not appear in the above list of metrics do not need to be added to extraMetrics.

To see a list of metrics that will be emitted you can run agent-status monitors after configuring this monitor in a running agent instance.