ZFS Adaptive Replacement Cache

Plugin: proc.plugin Module: /proc/spl/kstat/zfs/arcstats

Overview

This integration monitors ZFS Adadptive Replacement Cache (ARC) statistics.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Default Behavior

Auto-Detection

This integration doesn't support auto-detection.

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

Setup

Prerequisites

No action required.

Configuration

Options

There are no configuration options.

via File

There is no configuration file.

Examples

There are no configuration examples.

Alerts

The following alerts are available:

Alert name	On metric	Description
zfs_memory_throttle	zfs.memory_ops	number of times ZFS had to limit the ARC growth in the last 10 minutes

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per ZFS Adaptive Replacement Cache instance

This scope has no labels.

Metrics:

Metric	Description	Dimensions	Unit
zfs.arc_size	ZFS ARC Size	arcsz, target, min, max	MiB
zfs.l2_size	ZFS L2 ARC Size	actual, size	MiB
zfs.reads	ZFS Reads	arc, demand, prefetch, metadata, l2	reads/s
zfs.bytes	ZFS ARC L2 Read/Write Rate	read, write	KiB/s
zfs.hits	ZFS ARC Hits	hits, misses	percentage
zfs.hits_rate	ZFS ARC Hits Rate	hits, misses	events/s
zfs.dhits	ZFS Demand Hits	hits, misses	percentage
zfs.dhits_rate	ZFS Demand Hits Rate	hits, misses	events/s
zfs.phits	ZFS Prefetch Hits	hits, misses	percentage
zfs.phits_rate	ZFS Prefetch Hits Rate	hits, misses	events/s
zfs.mhits	ZFS Metadata Hits	hits, misses	percentage
zfs.mhits_rate	ZFS Metadata Hits Rate	hits, misses	events/s
zfs.l2hits	ZFS L2 Hits	hits, misses	percentage
zfs.l2hits_rate	ZFS L2 Hits Rate	hits, misses	events/s
zfs.list_hits	ZFS List Hits	mfu, mfu_ghost, mru, mru_ghost	hits/s
zfs.arc_size_breakdown	ZFS ARC Size Breakdown	recent, frequent	percentage
zfs.memory_ops	ZFS Memory Operations	direct, throttled, indirect	operations/s
zfs.important_ops	ZFS Important Operations	evict_skip, deleted, mutex_miss, hash_collisions	operations/s
zfs.actual_hits	ZFS Actual Cache Hits	hits, misses	percentage
zfs.actual_hits_rate	ZFS Actual Cache Hits Rate	hits, misses	events/s
zfs.demand_data_hits	ZFS Data Demand Efficiency	hits, misses	percentage
zfs.demand_data_hits_rate	ZFS Data Demand Efficiency Rate	hits, misses	events/s
zfs.prefetch_data_hits	ZFS Data Prefetch Efficiency	hits, misses	percentage
zfs.prefetch_data_hits_rate	ZFS Data Prefetch Efficiency Rate	hits, misses	events/s
zfs.hash_elements	ZFS ARC Hash Elements	current, max	elements
zfs.hash_chains	ZFS ARC Hash Chains	current, max	chains