1.\" 2.\" This file and its contents are supplied under the terms of the 3.\" Common Development and Distribution License ("CDDL"), version 1.0. 4.\" You may only use this file in accordance with the terms of version 5.\" 1.0 of the CDDL. 6.\" 7.\" A full copy of the text of the CDDL should have accompanied this 8.\" source. A copy of the CDDL is also available via the Internet at 9.\" http://www.illumos.org/license/CDDL. 10.\" 11.\" Copyright 2014 Adam Stevko. All rights reserved. 12.\" Copyright (c) 2015 by Delphix. All rights reserved. 13.\" Copyright (c) 2020 by AJ Jordan. All rights reserved. 14.\" 15.Dd May 26, 2021 16.Dt ARCSTAT 1 17.Os 18. 19.Sh NAME 20.Nm arcstat 21.Nd report ZFS ARC and L2ARC statistics 22.Sh SYNOPSIS 23.Nm 24.Op Fl havxp 25.Op Fl f Ar field Ns Op , Ns Ar field Ns ... 26.Op Fl o Ar file 27.Op Fl s Ar string 28.Op Ar interval 29.Op Ar count 30. 31.Sh DESCRIPTION 32.Nm 33prints various ZFS ARC and L2ARC statistics in vmstat-like fashion: 34.Bl -tag -width "l2asize" 35.It Sy c 36ARC target size 37.It Sy dh% 38Demand data hit percentage 39.It Sy dm% 40Demand data miss percentage 41.It Sy mfu 42MFU list hits per second 43.It Sy mh% 44Metadata hit percentage 45.It Sy mm% 46Metadata miss percentage 47.It Sy mru 48MRU list hits per second 49.It Sy ph% 50Prefetch hits percentage 51.It Sy pm% 52Prefetch miss percentage 53.It Sy dhit 54Demand data hits per second 55.It Sy dmis 56Demand data misses per second 57.It Sy hit% 58ARC hit percentage 59.It Sy hits 60ARC reads per second 61.It Sy mfug 62MFU ghost list hits per second 63.It Sy mhit 64Metadata hits per second 65.It Sy miss 66ARC misses per second 67.It Sy mmis 68Metadata misses per second 69.It Sy mrug 70MRU ghost list hits per second 71.It Sy phit 72Prefetch hits per second 73.It Sy pmis 74Prefetch misses per second 75.It Sy read 76Total ARC accesses per second 77.It Sy time 78Current time 79.It Sy size 80ARC size 81.It Sy arcsz 82Alias for 83.Sy size 84.It Sy dread 85Demand data accesses per second 86.It Sy eskip 87evict_skip per second 88.It Sy miss% 89ARC miss percentage 90.It Sy mread 91Metadata accesses per second 92.It Sy pread 93Prefetch accesses per second 94.It Sy l2hit% 95L2ARC access hit percentage 96.It Sy l2hits 97L2ARC hits per second 98.It Sy l2miss 99L2ARC misses per second 100.It Sy l2read 101Total L2ARC accesses per second 102.It Sy l2pref 103L2ARC prefetch allocated size per second 104.It Sy l2pref% 105L2ARC prefetch allocated size percentage 106.It Sy l2mfu 107L2ARC MFU allocated size per second 108.It Sy l2mfu% 109L2ARC MFU allocated size percentage 110.It Sy l2mru 111L2ARC MRU allocated size per second 112.It Sy l2mru% 113L2ARC MRU allocated size percentage 114.It Sy l2data 115L2ARC data (buf content) allocated size per second 116.It Sy l2data% 117L2ARC data (buf content) allocated size percentage 118.It Sy l2meta 119L2ARC metadata (buf content) allocated size per second 120.It Sy l2meta% 121L2ARC metadata (buf content) allocated size percentage 122.It Sy l2size 123Size of the L2ARC 124.It Sy mtxmis 125mutex_miss per second 126.It Sy l2bytes 127Bytes read per second from the L2ARC 128.It Sy l2miss% 129L2ARC access miss percentage 130.It Sy l2asize 131Actual (compressed) size of the L2ARC 132.It Sy grow 133ARC grow disabled 134.It Sy need 135ARC reclaim needed 136.It Sy free 137The ARC's idea of how much free memory there is, which includes evictable memory in the page cache. 138Since the ARC tries to keep 139.Sy avail 140above zero, 141.Sy avail 142is usually more instructive to observe than 143.Sy free . 144.It Sy avail 145The ARC's idea of how much free memory is available to it, which is a bit less than 146.Sy free . 147May temporarily be negative, in which case the ARC will reduce the target size 148.Sy c . 149.El 150. 151.Sh OPTIONS 152.Bl -tag -width "-v" 153.It Fl a 154Print all possible stats. 155.It Fl f 156Display only specific fields. 157See 158.Sy DESCRIPTION 159for supported statistics. 160.It Fl h 161Display help message. 162.It Fl o 163Report statistics to a file instead of the standard output. 164.It Fl p 165Disable auto-scaling of numerical fields (for raw, machine-parsable values). 166.It Fl s 167Display data with a specified separator (default: 2 spaces). 168.It Fl x 169Print extended stats (same as 170.Fl f Ar time,mfu,mru,mfug,mrug,eskip,mtxmis,dread,pread,read Ns No ). 171.It Fl v 172Show field headers and definitions 173.El 174. 175.Sh OPERANDS 176The following operands are supported: 177.Bl -tag -width "interval" 178.It Ar interval 179Specify the sampling interval in seconds. 180.It Ar count 181Display only \fIcount\fR reports. 182.El 183