# 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. ## 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 ](https://github.com/netdata/netdata/blob/master/health/health.d/zfs.conf) | zfs.memory_ops | number of times ZFS had to limit the ARC growth in the last 10 minutes | ## Setup ### Prerequisites No action required. ### Configuration #### File There is no configuration file. #### Options There are no configuration options. #### Examples There are no configuration examples.