1.\" SPDX-License-Identifier: CDDL-1.0 2.\" 3.\" CDDL HEADER START 4.\" 5.\" The contents of this file are subject to the terms of the 6.\" Common Development and Distribution License (the "License"). 7.\" You may not use this file except in compliance with the License. 8.\" 9.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10.\" or http://www.opensolaris.org/os/licensing. 11.\" See the License for the specific language governing permissions 12.\" and limitations under the License. 13.\" 14.\" When distributing Covered Code, include this CDDL HEADER in each 15.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16.\" If applicable, add the following below this CDDL HEADER, with the 17.\" fields enclosed by brackets "[]" replaced with your own identifying 18.\" information: Portions Copyright [yyyy] [name of copyright owner] 19.\" 20.\" CDDL HEADER END 21.\" 22.\" 23.\" Copyright (c) 2023, Klara Inc. 24.\" 25.Dd February 14, 2024 26.Dt ZPOOL-PREFETCH 8 27.Os 28. 29.Sh NAME 30.Nm zpool-prefetch 31.Nd Prefetches pool metadata into ARC 32.Sh SYNOPSIS 33.Nm zpool 34.Cm prefetch 35.Op Fl t Ar type 36.Ar pool 37.Sh DESCRIPTION 38Massively prefetch metadata of a specific type for the given pool into the ARC 39to reduce latency of some operations later. 40If no type is specified, all types are prefetched. 41.Pp 42The following types are supported: 43.Bl -tag -width "brt" 44.It Sy brt 45Prefetch the BRT (block reference table). 46This may improve performance for block cloning operations, 47and frees for earlier cloned blocks. 48.It Sy ddt 49Prefetch the DDT (deduplication table). 50This may improve performance of writes when deduplication is enabled, 51and frees for earlier deduplicated blocks. 52.El 53