1.\" SPDX-License-Identifier: CDDL-1.0 2.\" 3.\" This file and its contents are supplied under the terms of the 4.\" Common Development and Distribution License ("CDDL"), version 1.0. 5.\" You may only use this file in accordance with the terms of version 6.\" 1.0 of the CDDL. 7.\" 8.\" A full copy of the text of the CDDL should have accompanied this 9.\" source. A copy of the CDDL is also available via the Internet at 10.\" http://www.illumos.org/license/CDDL. 11.\" 12.\" Copyright 2014 Adam Stevko. All rights reserved. 13.\" Copyright (c) 2015 by Delphix. All rights reserved. 14.\" Copyright (c) 2020 by AJ Jordan. All rights reserved. 15.\" 16.Dd December 23, 2022 17.Dt ARCSTAT 1 18.Os 19. 20.Sh NAME 21.Nm arcstat 22.Nd report ZFS ARC and L2ARC statistics 23.Sh SYNOPSIS 24.Nm 25.Op Fl havxp 26.Op Fl f Ar field Ns Op , Ns Ar field Ns … 27.Op Fl o Ar file 28.Op Fl s Ar string 29.Op Ar interval 30.Op Ar count 31. 32.Sh DESCRIPTION 33.Nm 34prints various ZFS ARC and L2ARC statistics in vmstat-like fashion: 35.Bl -tag -compact -offset Ds -width "l2asize" 36.It Sy c 37ARC target size 38.It Sy dh% 39Demand hit percentage 40.It Sy di% 41Demand I/O hit percentage 42.It Sy dm% 43Demand miss percentage 44.It Sy ddh% 45Demand data hit percentage 46.It Sy ddi% 47Demand data I/O hit percentage 48.It Sy ddm% 49Demand data miss percentage 50.It Sy dmh% 51Demand metadata hit percentage 52.It Sy dmi% 53Demand metadata I/O hit percentage 54.It Sy dmm% 55Demand metadata miss percentage 56.It Sy mfu 57MFU list hits per second 58.It Sy mh% 59Metadata hit percentage 60.It Sy mi% 61Metadata I/O hit percentage 62.It Sy mm% 63Metadata miss percentage 64.It Sy mru 65MRU list hits per second 66.It Sy ph% 67Prefetch hits percentage 68.It Sy pi% 69Prefetch I/O hits percentage 70.It Sy pm% 71Prefetch miss percentage 72.It Sy pdh% 73Prefetch data hits percentage 74.It Sy pdi% 75Prefetch data I/O hits percentage 76.It Sy pdm% 77Prefetch data miss percentage 78.It Sy pmh% 79Prefetch metadata hits percentage 80.It Sy pmi% 81Prefetch metadata I/O hits percentage 82.It Sy pmm% 83Prefetch metadata miss percentage 84.It Sy dhit 85Demand hits per second 86.It Sy dioh 87Demand I/O hits per second 88.It Sy dmis 89Demand misses per second 90.It Sy ddhit 91Demand data hits per second 92.It Sy ddioh 93Demand data I/O hits per second 94.It Sy ddmis 95Demand data misses per second 96.It Sy dmhit 97Demand metadata hits per second 98.It Sy dmioh 99Demand metadata I/O hits per second 100.It Sy dmmis 101Demand metadata misses per second 102.It Sy hit% 103ARC hit percentage 104.It Sy hits 105ARC hits per second 106.It Sy ioh% 107ARC I/O hits percentage 108.It Sy iohs 109ARC I/O hits per second 110.It Sy mfug 111MFU ghost list hits per second 112.It Sy mhit 113Metadata hits per second 114.It Sy mioh 115Metadata I/O hits per second 116.It Sy miss 117ARC misses per second 118.It Sy mmis 119Metadata misses per second 120.It Sy mrug 121MRU ghost list hits per second 122.It Sy phit 123Prefetch hits per second 124.It Sy pioh 125Prefetch I/O hits per second 126.It Sy pmis 127Prefetch misses per second 128.It Sy pdhit 129Prefetch data hits per second 130.It Sy pdioh 131Prefetch data I/O hits per second 132.It Sy pdmis 133Prefetch data misses per second 134.It Sy pmhit 135Prefetch metadata hits per second 136.It Sy pmioh 137Prefetch metadata I/O hits per second 138.It Sy pmmis 139Prefetch metadata misses per second 140.It Sy read 141Total ARC accesses per second 142.It Sy time 143Current time 144.It Sy size 145ARC size 146.It Sy arcsz 147Alias for 148.Sy size 149.It Sy unc 150Uncached list hits per second 151.It Sy dread 152Demand accesses per second 153.It Sy ddread 154Demand data accesses per second 155.It Sy dmread 156Demand metadata accesses per second 157.It Sy eskip 158evict_skip per second 159.It Sy miss% 160ARC miss percentage 161.It Sy mread 162Metadata accesses per second 163.It Sy pread 164Prefetch accesses per second 165.It Sy pdread 166Prefetch data accesses per second 167.It Sy pmread 168Prefetch metadata accesses per second 169.It Sy l2hit% 170L2ARC access hit percentage 171.It Sy l2hits 172L2ARC hits per second 173.It Sy l2miss 174L2ARC misses per second 175.It Sy l2read 176Total L2ARC accesses per second 177.It Sy l2pref 178L2ARC prefetch allocated size per second 179.It Sy l2pref% 180L2ARC prefetch allocated size percentage 181.It Sy l2mfu 182L2ARC MFU allocated size per second 183.It Sy l2mfu% 184L2ARC MFU allocated size percentage 185.It Sy l2mru 186L2ARC MRU allocated size per second 187.It Sy l2mru% 188L2ARC MRU allocated size percentage 189.It Sy l2data 190L2ARC data (buf content) allocated size per second 191.It Sy l2data% 192L2ARC data (buf content) allocated size percentage 193.It Sy l2meta 194L2ARC metadata (buf content) allocated size per second 195.It Sy l2meta% 196L2ARC metadata (buf content) allocated size percentage 197.It Sy l2size 198Size of the L2ARC 199.It Sy mtxmis 200mutex_miss per second 201.It Sy l2bytes 202Bytes read per second from the L2ARC 203.It Sy l2wbytes 204Bytes written per second to the L2ARC 205.It Sy l2miss% 206L2ARC access miss percentage 207.It Sy l2asize 208Actual (compressed) size of the L2ARC 209.It Sy cmpsz 210Compressed size 211.It Sy cmpsz% 212Compressed size percentage 213.It Sy ovhsz 214Overhead size 215.It Sy ovhsz% 216Overhead size percentage 217.It Sy bonsz 218Bonus size 219.It Sy bonsz% 220Bonus size percentage 221.It Sy dnosz 222Dnode size 223.It Sy dnosz% 224Dnode size percentage 225.It Sy dbusz 226Dbuf size 227.It Sy dbusz% 228Dbuf size percentage 229.It Sy hdrsz 230Header size 231.It Sy hdrsz% 232Header size percentage 233.It Sy l2hsz 234L2 header size 235.It Sy l2hsz% 236L2 header size percentage 237.It Sy abdsz 238ABD chunk waste size 239.It Sy abdsz% 240ABD chunk waste size percentage 241.It Sy datatg 242ARC data target 243.It Sy datatg% 244ARC data target percentage 245.It Sy datasz 246ARC data size 247.It Sy datasz% 248ARC data size percentage 249.It Sy metatg 250ARC metadata target 251.It Sy metatg% 252ARC metadata target percentage 253.It Sy metasz 254ARC metadata size 255.It Sy metasz% 256ARC metadata size percentage 257.It Sy anosz 258Anonymous size 259.It Sy anosz% 260Anonymous size percentage 261.It Sy anoda 262Anonymous data size 263.It Sy anoda% 264Anonymous data size percentage 265.It Sy anome 266Anonymous metadata size 267.It Sy anome% 268Anonymous metadata size percentage 269.It Sy anoed 270Anonymous evictable data size 271.It Sy anoed% 272Anonymous evictable data size percentage 273.It Sy anoem 274Anonymous evictable metadata size 275.It Sy anoem% 276Anonymous evictable metadata size percentage 277.It Sy mfutg 278MFU target 279.It Sy mfutg% 280MFU target percentage 281.It Sy mfudt 282MFU data target 283.It Sy mfudt% 284MFU data target percentage 285.It Sy mfumt 286MFU metadata target 287.It Sy mfumt% 288MFU metadata target percentage 289.It Sy mfusz 290MFU size 291.It Sy mfusz% 292MFU size percentage 293.It Sy mfuda 294MFU data size 295.It Sy mfuda% 296MFU data size percentage 297.It Sy mfume 298MFU metadata size 299.It Sy mfume% 300MFU metadata size percentage 301.It Sy mfued 302MFU evictable data size 303.It Sy mfued% 304MFU evictable data size percentage 305.It Sy mfuem 306MFU evictable metadata size 307.It Sy mfuem% 308MFU evictable metadata size percentage 309.It Sy mfugsz 310MFU ghost size 311.It Sy mfugd 312MFU ghost data size 313.It Sy mfugm 314MFU ghost metadata size 315.It Sy mrutg 316MRU target 317.It Sy mrutg% 318MRU target percentage 319.It Sy mrudt 320MRU data target 321.It Sy mrudt% 322MRU data target percentage 323.It Sy mrumt 324MRU metadata target 325.It Sy mrumt% 326MRU metadata target percentage 327.It Sy mrusz 328MRU size 329.It Sy mrusz% 330MRU size percentage 331.It Sy mruda 332MRU data size 333.It Sy mruda% 334MRU data size percentage 335.It Sy mrume 336MRU metadata size 337.It Sy mrume% 338MRU metadata size percentage 339.It Sy mrued 340MRU evictable data size 341.It Sy mrued% 342MRU evictable data size percentage 343.It Sy mruem 344MRU evictable metadata size 345.It Sy mruem% 346MRU evictable metadata size percentage 347.It Sy mrugsz 348MRU ghost size 349.It Sy mrugd 350MRU ghost data size 351.It Sy mrugm 352MRU ghost metadata size 353.It Sy uncsz 354Uncached size 355.It Sy uncsz% 356Uncached size percentage 357.It Sy uncda 358Uncached data size 359.It Sy uncda% 360Uncached data size percentage 361.It Sy uncme 362Uncached metadata size 363.It Sy uncme% 364Uncached metadata size percentage 365.It Sy unced 366Uncached evictable data size 367.It Sy unced% 368Uncached evictable data size percentage 369.It Sy uncem 370Uncached evictable metadata size 371.It Sy uncem% 372Uncached evictable metadata size percentage 373.It Sy grow 374ARC grow disabled 375.It Sy need 376ARC reclaim needed 377.It Sy free 378The ARC's idea of how much free memory there is, which includes evictable memory 379in the page cache. 380Since the ARC tries to keep 381.Sy avail 382above zero, 383.Sy avail 384is usually more instructive to observe than 385.Sy free . 386.It Sy avail 387The ARC's idea of how much free memory is available to it, which is a bit less 388than 389.Sy free . 390May temporarily be negative, in which case the ARC will reduce the target size 391.Sy c . 392.El 393. 394.Sh OPTIONS 395.Bl -tag -width "-v" 396.It Fl a 397Print all possible stats. 398.It Fl f 399Display only specific fields. 400See 401.Sx DESCRIPTION 402for supported statistics. 403.It Fl h 404Display help message. 405.It Fl o 406Report statistics to a file instead of the standard output. 407.It Fl p 408Disable auto-scaling of numerical fields (for raw, machine-parsable values). 409.It Fl s 410Display data with a specified separator (default: 2 spaces). 411.It Fl x 412Print extended stats 413.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 . 414.It Fl v 415Show field headers and definitions 416.El 417. 418.Sh OPERANDS 419The following operands are supported: 420.Bl -tag -compact -offset Ds -width "interval" 421.It Ar interval 422Specify the sampling interval in seconds. 423.It Ar count 424Display only 425.Ar count 426reports. 427.El 428