ZFS Adaptive Replacement Cache
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
File
There is no configuration file.
Options
There are no configuration options.
Examples
There are no configuration examples.
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 | Dimensions | Unit |
|---|---|---|
| zfs.arc_size | arcsz, target, min, max | MiB |
| zfs.l2_size | actual, size | MiB |
| zfs.reads | arc, demand, prefetch, metadata, l2 | reads/s |
| zfs.bytes | read, write | KiB/s |
| zfs.hits | hits, misses | percentage |
| zfs.hits_rate | hits, misses | events/s |
| zfs.dhits | hits, misses | percentage |
| zfs.dhits_rate | hits, misses | events/s |
| zfs.phits | hits, misses | percentage |
| zfs.phits_rate | hits, misses | events/s |
| zfs.mhits | hits, misses | percentage |
| zfs.mhits_rate | hits, misses | events/s |
| zfs.l2hits | hits, misses | percentage |
| zfs.l2hits_rate | hits, misses | events/s |
| zfs.list_hits | mfu, mfu_ghost, mru, mru_ghost | hits/s |
| zfs.arc_size_breakdown | recent, frequent | percentage |
| zfs.memory_ops | direct, throttled, indirect | operations/s |
| zfs.important_ops | evict_skip, deleted, mutex_miss, hash_collisions | operations/s |
| zfs.actual_hits | hits, misses | percentage |
| zfs.actual_hits_rate | hits, misses | events/s |
| zfs.demand_data_hits | hits, misses | percentage |
| zfs.demand_data_hits_rate | hits, misses | events/s |
| zfs.prefetch_data_hits | hits, misses | percentage |
| zfs.prefetch_data_hits_rate | hits, misses | events/s |
| zfs.hash_elements | current, max | elements |
| zfs.hash_chains | current, max | chains |
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 |