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 December 23, 2022 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 -compact -offset Ds -width "l2asize" 35.It Sy c 36ARC target size 37.It Sy dh% 38Demand hit percentage 39.It Sy di% 40Demand I/O hit percentage 41.It Sy dm% 42Demand miss percentage 43.It Sy ddh% 44Demand data hit percentage 45.It Sy ddi% 46Demand data I/O hit percentage 47.It Sy ddm% 48Demand data miss percentage 49.It Sy dmh% 50Demand metadata hit percentage 51.It Sy dmi% 52Demand metadata I/O hit percentage 53.It Sy dmm% 54Demand metadata miss percentage 55.It Sy mfu 56MFU list hits per second 57.It Sy mh% 58Metadata hit percentage 59.It Sy mi% 60Metadata I/O hit percentage 61.It Sy mm% 62Metadata miss percentage 63.It Sy mru 64MRU list hits per second 65.It Sy ph% 66Prefetch hits percentage 67.It Sy pi% 68Prefetch I/O hits percentage 69.It Sy pm% 70Prefetch miss percentage 71.It Sy pdh% 72Prefetch data hits percentage 73.It Sy pdi% 74Prefetch data I/O hits percentage 75.It Sy pdm% 76Prefetch data miss percentage 77.It Sy pmh% 78Prefetch metadata hits percentage 79.It Sy pmi% 80Prefetch metadata I/O hits percentage 81.It Sy pmm% 82Prefetch metadata miss percentage 83.It Sy dhit 84Demand hits per second 85.It Sy dioh 86Demand I/O hits per second 87.It Sy dmis 88Demand misses per second 89.It Sy ddhit 90Demand data hits per second 91.It Sy ddioh 92Demand data I/O hits per second 93.It Sy ddmis 94Demand data misses per second 95.It Sy dmhit 96Demand metadata hits per second 97.It Sy dmioh 98Demand metadata I/O hits per second 99.It Sy dmmis 100Demand metadata misses per second 101.It Sy hit% 102ARC hit percentage 103.It Sy hits 104ARC hits per second 105.It Sy ioh% 106ARC I/O hits percentage 107.It Sy iohs 108ARC I/O hits per second 109.It Sy mfug 110MFU ghost list hits per second 111.It Sy mhit 112Metadata hits per second 113.It Sy mioh 114Metadata I/O hits per second 115.It Sy miss 116ARC misses per second 117.It Sy mmis 118Metadata misses per second 119.It Sy mrug 120MRU ghost list hits per second 121.It Sy phit 122Prefetch hits per second 123.It Sy pioh 124Prefetch I/O hits per second 125.It Sy pmis 126Prefetch misses per second 127.It Sy pdhit 128Prefetch data hits per second 129.It Sy pdioh 130Prefetch data I/O hits per second 131.It Sy pdmis 132Prefetch data misses per second 133.It Sy pmhit 134Prefetch metadata hits per second 135.It Sy pmioh 136Prefetch metadata I/O hits per second 137.It Sy pmmis 138Prefetch metadata misses per second 139.It Sy read 140Total ARC accesses per second 141.It Sy time 142Current time 143.It Sy size 144ARC size 145.It Sy arcsz 146Alias for 147.Sy size 148.It Sy unc 149Uncached list hits per second 150.It Sy dread 151Demand accesses per second 152.It Sy ddread 153Demand data accesses per second 154.It Sy dmread 155Demand metadata accesses per second 156.It Sy eskip 157evict_skip per second 158.It Sy miss% 159ARC miss percentage 160.It Sy mread 161Metadata accesses per second 162.It Sy pread 163Prefetch accesses per second 164.It Sy pdread 165Prefetch data accesses per second 166.It Sy pmread 167Prefetch metadata accesses per second 168.It Sy l2hit% 169L2ARC access hit percentage 170.It Sy l2hits 171L2ARC hits per second 172.It Sy l2miss 173L2ARC misses per second 174.It Sy l2read 175Total L2ARC accesses per second 176.It Sy l2pref 177L2ARC prefetch allocated size per second 178.It Sy l2pref% 179L2ARC prefetch allocated size percentage 180.It Sy l2mfu 181L2ARC MFU allocated size per second 182.It Sy l2mfu% 183L2ARC MFU allocated size percentage 184.It Sy l2mru 185L2ARC MRU allocated size per second 186.It Sy l2mru% 187L2ARC MRU allocated size percentage 188.It Sy l2data 189L2ARC data (buf content) allocated size per second 190.It Sy l2data% 191L2ARC data (buf content) allocated size percentage 192.It Sy l2meta 193L2ARC metadata (buf content) allocated size per second 194.It Sy l2meta% 195L2ARC metadata (buf content) allocated size percentage 196.It Sy l2size 197Size of the L2ARC 198.It Sy mtxmis 199mutex_miss per second 200.It Sy l2bytes 201Bytes read per second from the L2ARC 202.It Sy l2miss% 203L2ARC access miss percentage 204.It Sy l2asize 205Actual (compressed) size of the L2ARC 206.It Sy grow 207ARC grow disabled 208.It Sy need 209ARC reclaim needed 210.It Sy free 211The ARC's idea of how much free memory there is, which includes evictable memory 212in the page cache. 213Since the ARC tries to keep 214.Sy avail 215above zero, 216.Sy avail 217is usually more instructive to observe than 218.Sy free . 219.It Sy avail 220The ARC's idea of how much free memory is available to it, which is a bit less 221than 222.Sy free . 223May temporarily be negative, in which case the ARC will reduce the target size 224.Sy c . 225.El 226. 227.Sh OPTIONS 228.Bl -tag -width "-v" 229.It Fl a 230Print all possible stats. 231.It Fl f 232Display only specific fields. 233See 234.Sx DESCRIPTION 235for supported statistics. 236.It Fl h 237Display help message. 238.It Fl o 239Report statistics to a file instead of the standard output. 240.It Fl p 241Disable auto-scaling of numerical fields (for raw, machine-parsable values). 242.It Fl s 243Display data with a specified separator (default: 2 spaces). 244.It Fl x 245Print extended stats 246.Pq same as Fl f Sy time , Ns Sy mfu , Ns Sy mru , Ns Sy mfug , Ns Sy mrug , Ns Sy eskip , Ns Sy mtxmis , Ns Sy dread , Ns Sy pread , Ns Sy read . 247.It Fl v 248Show field headers and definitions 249.El 250. 251.Sh OPERANDS 252The following operands are supported: 253.Bl -tag -compact -offset Ds -width "interval" 254.It Ar interval 255Specify the sampling interval in seconds. 256.It Ar count 257Display only 258.Ar count 259reports. 260.El 261