ZARCSTAT(1) General Commands Manual ZARCSTAT(1)

# [NAME](#NAME)

`zarcstat` — report ZFS ARC and L2ARC statistics

# [SYNOPSIS](#SYNOPSIS)

`zarcstat` \[`-havxp`] \[`-f` `field`\[,`field`…]] \[`-o` `file`] \[`-s` `string`] \[`interval`] \[`count`]

# [DESCRIPTION](#DESCRIPTION)

`zarcstat` prints various ZFS ARC and L2ARC statistics in vmstat-like fashion:

[**c**](#c)

ARC target size

[**dh%**](#dh_)

Demand hit percentage

[**di%**](#di_)

Demand I/O hit percentage

[**dm%**](#dm_)

Demand miss percentage

[**ddh%**](#ddh_)

Demand data hit percentage

[**ddi%**](#ddi_)

Demand data I/O hit percentage

[**ddm%**](#ddm_)

Demand data miss percentage

[**dmh%**](#dmh_)

Demand metadata hit percentage

[**dmi%**](#dmi_)

Demand metadata I/O hit percentage

[**dmm%**](#dmm_)

Demand metadata miss percentage

[**mfu**](#mfu)

MFU list hits per second

[**mh%**](#mh_)

Metadata hit percentage

[**mi%**](#mi_)

Metadata I/O hit percentage

[**mm%**](#mm_)

Metadata miss percentage

[**mru**](#mru)

MRU list hits per second

[**ph%**](#ph_)

Prefetch hits percentage

[**pi%**](#pi_)

Prefetch I/O hits percentage

[**pm%**](#pm_)

Prefetch miss percentage

[**pdh%**](#pdh_)

Prefetch data hits percentage

[**pdi%**](#pdi_)

Prefetch data I/O hits percentage

[**pdm%**](#pdm_)

Prefetch data miss percentage

[**pmh%**](#pmh_)

Prefetch metadata hits percentage

[**pmi%**](#pmi_)

Prefetch metadata I/O hits percentage

[**pmm%**](#pmm_)

Prefetch metadata miss percentage

[**dhit**](#dhit)

Demand hits per second

[**dioh**](#dioh)

Demand I/O hits per second

[**dmis**](#dmis)

Demand misses per second

[**ddhit**](#ddhit)

Demand data hits per second

[**ddioh**](#ddioh)

Demand data I/O hits per second

[**ddmis**](#ddmis)

Demand data misses per second

[**dmhit**](#dmhit)

Demand metadata hits per second

[**dmioh**](#dmioh)

Demand metadata I/O hits per second

[**dmmis**](#dmmis)

Demand metadata misses per second

[**hit%**](#hit_)

ARC hit percentage

[**hits**](#hits)

ARC hits per second

[**ioh%**](#ioh_)

ARC I/O hits percentage

[**iohs**](#iohs)

ARC I/O hits per second

[**mfug**](#mfug)

MFU ghost list hits per second

[**mhit**](#mhit)

Metadata hits per second

[**mioh**](#mioh)

Metadata I/O hits per second

[**miss**](#miss)

ARC misses per second

[**mmis**](#mmis)

Metadata misses per second

[**mrug**](#mrug)

MRU ghost list hits per second

[**phit**](#phit)

Prefetch hits per second

[**pioh**](#pioh)

Prefetch I/O hits per second

[**pmis**](#pmis)

Prefetch misses per second

[**pdhit**](#pdhit)

Prefetch data hits per second

[**pdioh**](#pdioh)

Prefetch data I/O hits per second

[**pdmis**](#pdmis)

Prefetch data misses per second

[**pmhit**](#pmhit)

Prefetch metadata hits per second

[**pmioh**](#pmioh)

Prefetch metadata I/O hits per second

[**pmmis**](#pmmis)

Prefetch metadata misses per second

[**read**](#read)

Total ARC accesses per second

[**time**](#time)

Current time

[**size**](#size)

ARC size

[**arcsz**](#arcsz)

Alias for **size**

[**unc**](#unc)

Uncached list hits per second

[**dread**](#dread)

Demand accesses per second

[**ddread**](#ddread)

Demand data accesses per second

[**dmread**](#dmread)

Demand metadata accesses per second

[**eskip**](#eskip)

evict\_skip per second

[**miss%**](#miss_)

ARC miss percentage

[**mread**](#mread)

Metadata accesses per second

[**pread**](#pread)

Prefetch accesses per second

[**pdread**](#pdread)

Prefetch data accesses per second

[**pmread**](#pmread)

Prefetch metadata accesses per second

[**l2hit%**](#l2hit_)

L2ARC access hit percentage

[**l2hits**](#l2hits)

L2ARC hits per second

[**l2miss**](#l2miss)

L2ARC misses per second

[**l2read**](#l2read)

Total L2ARC accesses per second

[**l2pref**](#l2pref)

L2ARC prefetch allocated size per second

[**l2pref%**](#l2pref_)

L2ARC prefetch allocated size percentage

[**l2mfu**](#l2mfu)

L2ARC MFU allocated size per second

[**l2mfu%**](#l2mfu_)

L2ARC MFU allocated size percentage

[**l2mru**](#l2mru)

L2ARC MRU allocated size per second

[**l2mru%**](#l2mru_)

L2ARC MRU allocated size percentage

[**l2data**](#l2data)

L2ARC data (buf content) allocated size per second

[**l2data%**](#l2data_)

L2ARC data (buf content) allocated size percentage

[**l2meta**](#l2meta)

L2ARC metadata (buf content) allocated size per second

[**l2meta%**](#l2meta_)

L2ARC metadata (buf content) allocated size percentage

[**l2size**](#l2size)

Size of the L2ARC

[**mtxmis**](#mtxmis)

mutex\_miss per second

[**l2bytes**](#l2bytes)

Bytes read per second from the L2ARC

[**l2wbytes**](#l2wbytes)

Bytes written per second to the L2ARC

[**l2miss%**](#l2miss_)

L2ARC access miss percentage

[**l2asize**](#l2asize)

Actual (compressed) size of the L2ARC

[**cmpsz**](#cmpsz)

Compressed size

[**cmpsz%**](#cmpsz_)

Compressed size percentage

[**ovhsz**](#ovhsz)

Overhead size

[**ovhsz%**](#ovhsz_)

Overhead size percentage

[**bonsz**](#bonsz)

Bonus size

[**bonsz%**](#bonsz_)

Bonus size percentage

[**dnosz**](#dnosz)

Dnode size

[**dnosz%**](#dnosz_)

Dnode size percentage

[**dbusz**](#dbusz)

Dbuf size

[**dbusz%**](#dbusz_)

Dbuf size percentage

[**hdrsz**](#hdrsz)

Header size

[**hdrsz%**](#hdrsz_)

Header size percentage

[**l2hsz**](#l2hsz)

L2 header size

[**l2hsz%**](#l2hsz_)

L2 header size percentage

[**abdsz**](#abdsz)

ABD chunk waste size

[**abdsz%**](#abdsz_)

ABD chunk waste size percentage

[**datatg**](#datatg)

ARC data target

[**datatg%**](#datatg_)

ARC data target percentage

[**datasz**](#datasz)

ARC data size

[**datasz%**](#datasz_)

ARC data size percentage

[**metatg**](#metatg)

ARC metadata target

[**metatg%**](#metatg_)

ARC metadata target percentage

[**metasz**](#metasz)

ARC metadata size

[**metasz%**](#metasz_)

ARC metadata size percentage

[**anosz**](#anosz)

Anonymous size

[**anosz%**](#anosz_)

Anonymous size percentage

[**anoda**](#anoda)

Anonymous data size

[**anoda%**](#anoda_)

Anonymous data size percentage

[**anome**](#anome)

Anonymous metadata size

[**anome%**](#anome_)

Anonymous metadata size percentage

[**anoed**](#anoed)

Anonymous evictable data size

[**anoed%**](#anoed_)

Anonymous evictable data size percentage

[**anoem**](#anoem)

Anonymous evictable metadata size

[**anoem%**](#anoem_)

Anonymous evictable metadata size percentage

[**mfutg**](#mfutg)

MFU target

[**mfutg%**](#mfutg_)

MFU target percentage

[**mfudt**](#mfudt)

MFU data target

[**mfudt%**](#mfudt_)

MFU data target percentage

[**mfumt**](#mfumt)

MFU metadata target

[**mfumt%**](#mfumt_)

MFU metadata target percentage

[**mfusz**](#mfusz)

MFU size

[**mfusz%**](#mfusz_)

MFU size percentage

[**mfuda**](#mfuda)

MFU data size

[**mfuda%**](#mfuda_)

MFU data size percentage

[**mfume**](#mfume)

MFU metadata size

[**mfume%**](#mfume_)

MFU metadata size percentage

[**mfued**](#mfued)

MFU evictable data size

[**mfued%**](#mfued_)

MFU evictable data size percentage

[**mfuem**](#mfuem)

MFU evictable metadata size

[**mfuem%**](#mfuem_)

MFU evictable metadata size percentage

[**mfugsz**](#mfugsz)

MFU ghost size

[**mfugd**](#mfugd)

MFU ghost data size

[**mfugm**](#mfugm)

MFU ghost metadata size

[**mrutg**](#mrutg)

MRU target

[**mrutg%**](#mrutg_)

MRU target percentage

[**mrudt**](#mrudt)

MRU data target

[**mrudt%**](#mrudt_)

MRU data target percentage

[**mrumt**](#mrumt)

MRU metadata target

[**mrumt%**](#mrumt_)

MRU metadata target percentage

[**mrusz**](#mrusz)

MRU size

[**mrusz%**](#mrusz_)

MRU size percentage

[**mruda**](#mruda)

MRU data size

[**mruda%**](#mruda_)

MRU data size percentage

[**mrume**](#mrume)

MRU metadata size

[**mrume%**](#mrume_)

MRU metadata size percentage

[**mrued**](#mrued)

MRU evictable data size

[**mrued%**](#mrued_)

MRU evictable data size percentage

[**mruem**](#mruem)

MRU evictable metadata size

[**mruem%**](#mruem_)

MRU evictable metadata size percentage

[**mrugsz**](#mrugsz)

MRU ghost size

[**mrugd**](#mrugd)

MRU ghost data size

[**mrugm**](#mrugm)

MRU ghost metadata size

[**uncsz**](#uncsz)

Uncached size

[**uncsz%**](#uncsz_)

Uncached size percentage

[**uncda**](#uncda)

Uncached data size

[**uncda%**](#uncda_)

Uncached data size percentage

[**uncme**](#uncme)

Uncached metadata size

[**uncme%**](#uncme_)

Uncached metadata size percentage

[**unced**](#unced)

Uncached evictable data size

[**unced%**](#unced_)

Uncached evictable data size percentage

[**uncem**](#uncem)

Uncached evictable metadata size

[**uncem%**](#uncem_)

Uncached evictable metadata size percentage

[**grow**](#grow)

ARC grow disabled

[**need**](#need)

ARC reclaim needed

[**free**](#free)

The ARC's idea of how much free memory there is, which includes evictable memory in the page cache. Since the ARC tries to keep **avail** above zero, **avail** is usually more instructive to observe than **free**.

[**avail**](#avail)

The ARC's idea of how much free memory is available to it, which is a bit less than **free**. May temporarily be negative, in which case the ARC will reduce the target size **c**.

# [OPTIONS](#OPTIONS)

[`-a`](#a)

Print all possible stats.

[`-f`](#f)

Display only specific fields. See [DESCRIPTION](#DESCRIPTION) for supported statistics.

[`-h`](#h)

Display help message.

[`-o`](#o)

Report statistics to a file instead of the standard output.

[`-p`](#p)

Disable auto-scaling of numerical fields (for raw, machine-parsable values).

[`-s`](#s)

Display data with a specified separator (default: 2 spaces).

[`-x`](#x)

Print extended stats (same as `-f` **time**,**mfu**,**mru**,**mfug**,**mrug**,**eskip**,**mtxmis**,**dread**,**pread**,**read**).

[`-v`](#v)

Show field headers and definitions

# [OPERANDS](#OPERANDS)

The following operands are supported:

`interval`

Specify the sampling interval in seconds.

`count`

Display only `count` reports.

September 19, 2024 OpenZFS

---

Document: zarcstat(1) from zfs 2.4.4-r3 (Chainguard OS)
Source: https://github.com/openzfs/zfs