mirror_zfs/man/man8/zpool-scrub.8

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.\" Copyright (c) 2007, Sun Microsystems, Inc. All Rights Reserved.
.\" Copyright (c) 2012, 2018 by Delphix. All rights reserved.
.\" Copyright (c) 2012 Cyril Plisko. All Rights Reserved.
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.Dd August 9, 2019
.Dt ZPOOL-SCRUB 8
.Os Linux
.Sh NAME
.Nm zpool Ns Pf - Cm scrub
.Nd Begin a scrub or resume a paused scrub of a ZFS storage pool
.Sh SYNOPSIS
.Nm
.Cm scrub
.Op Fl s | Fl p
.Op Fl w
.Ar pool Ns ...
.Sh DESCRIPTION
.Bl -tag -width Ds
.It Xo
.Nm
.Cm scrub
.Op Fl s | Fl p
.Op Fl w
.Ar pool Ns ...
.Xc
Begins a scrub or resumes a paused scrub.
The scrub examines all data in the specified pools to verify that it checksums
correctly.
For replicated
.Pq mirror or raidz
devices, ZFS automatically repairs any damage discovered during the scrub.
The
.Nm zpool Cm status
command reports the progress of the scrub and summarizes the results of the
scrub upon completion.
.Pp
Scrubbing and resilvering are very similar operations.
The difference is that resilvering only examines data that ZFS knows to be out
of date
.Po
for example, when attaching a new device to a mirror or replacing an existing
device
.Pc ,
whereas scrubbing examines all data to discover silent errors due to hardware
faults or disk failure.
.Pp
Because scrubbing and resilvering are I/O-intensive operations, ZFS only allows
one at a time.
If a scrub is paused, the
.Nm zpool Cm scrub
resumes it.
If a resilver is in progress, ZFS does not allow a scrub to be started until the
resilver completes.
.Pp
Note that, due to changes in pool data on a live system, it is possible for
scrubs to progress slightly beyond 100% completion. During this period, no
completion time estimate will be provided.
.Bl -tag -width Ds
.It Fl s
Stop scrubbing.
.El
.Bl -tag -width Ds
.It Fl p
Pause scrubbing.
Scrub pause state and progress are periodically synced to disk.
If the system is restarted or pool is exported during a paused scrub,
even after import, scrub will remain paused until it is resumed.
Once resumed the scrub will pick up from the place where it was last
checkpointed to disk.
To resume a paused scrub issue
.Nm zpool Cm scrub
again.
.It Fl w
Wait until scrub has completed before returning.
.El
.El
.Sh SEE ALSO
.Xr zpool-iostat 8 ,
.Xr zpool-resilver 8 ,
.Xr zpool-status 8
Reorganize zpool(8) man page into sections Moved subcommand topics into individual manpages. Reordered and grouped the list of subcommands by topic. Moved concepts overview to `zpoolconcepts.8` and the long list of available pool properties to `zpoolprops.8`. Internal cross-references copied from `zpool.8` needed to be converted to `.Xr` external references to new subcommand manual pages. Move `autotrim` into lexical order, autotrim tacked onto the end of a list. Now it is in alphabetical order. Clarify attach/detach description. Description was too specific to command syntax. Overview clarifies reason for attaching or detaching a device. Clarify replace description, don't refer to subcommand arguments. Clarify split command description, say what split actually does and why you'd want to do it. Clarify description of upgrade, and simplify the zpool.8 wording of the zpool-upgrade(8) description. Clarify description of import, detail what zpool-import(8) actually does. Add appropriate SEE ALSO sections. Divided zpool subcommand manual pages need their own SEE ALSO sections. Also modified fsck.zfs.8 to point directly to zfs-scrub.8 and zed.8.in to include a direct reference to zfs-events.8 Reviewed-by: Matt Ahrens <matt@delphix.com> Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Ross Williams <ross@ross-williams.net> Closes #9564 2019-11-13 20:21:07 +03:00			`.\"`
			`.\" CDDL HEADER START`
			`.\"`
			`.\" The contents of this file are subject to the terms of the`
			`.\" Common Development and Distribution License (the "License").`
			`.\" You may not use this file except in compliance with the License.`
			`.\"`
			`.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE`
			`.\" or http://www.opensolaris.org/os/licensing.`
			`.\" See the License for the specific language governing permissions`
			`.\" and limitations under the License.`
			`.\"`
			`.\" When distributing Covered Code, include this CDDL HEADER in each`
			`.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE.`
			`.\" If applicable, add the following below this CDDL HEADER, with the`
			`.\" fields enclosed by brackets "[]" replaced with your own identifying`
			`.\" information: Portions Copyright [yyyy] [name of copyright owner]`
			`.\"`
			`.\" CDDL HEADER END`
			`.\"`
			`.\"`
			`.\" Copyright (c) 2007, Sun Microsystems, Inc. All Rights Reserved.`
			`.\" Copyright (c) 2012, 2018 by Delphix. All rights reserved.`
			`.\" Copyright (c) 2012 Cyril Plisko. All Rights Reserved.`
			`.\" Copyright (c) 2017 Datto Inc.`
			`.\" Copyright (c) 2018 George Melikov. All Rights Reserved.`
			`.\" Copyright 2017 Nexenta Systems, Inc.`
			`.\" Copyright (c) 2017 Open-E, Inc. All Rights Reserved.`
			`.\"`
			`.Dd August 9, 2019`
			`.Dt ZPOOL-SCRUB 8`
			`.Os Linux`
			`.Sh NAME`
			`.Nm zpool Ns Pf - Cm scrub`
			`.Nd Begin a scrub or resume a paused scrub of a ZFS storage pool`
			`.Sh SYNOPSIS`
			`.Nm`
			`.Cm scrub`
			`.Op Fl s \| Fl p`
			`.Op Fl w`
			`.Ar pool Ns ...`
			`.Sh DESCRIPTION`
			`.Bl -tag -width Ds`
			`.It Xo`
			`.Nm`
			`.Cm scrub`
			`.Op Fl s \| Fl p`
			`.Op Fl w`
			`.Ar pool Ns ...`
			`.Xc`
			`Begins a scrub or resumes a paused scrub.`
			`The scrub examines all data in the specified pools to verify that it checksums`
			`correctly.`
			`For replicated`
			`.Pq mirror or raidz`
			`devices, ZFS automatically repairs any damage discovered during the scrub.`
			`The`
			`.Nm zpool Cm status`
			`command reports the progress of the scrub and summarizes the results of the`
			`scrub upon completion.`
			`.Pp`
			`Scrubbing and resilvering are very similar operations.`
			`The difference is that resilvering only examines data that ZFS knows to be out`
			`of date`
			`.Po`
			`for example, when attaching a new device to a mirror or replacing an existing`
			`device`
			`.Pc ,`
			`whereas scrubbing examines all data to discover silent errors due to hardware`
			`faults or disk failure.`
			`.Pp`
			`Because scrubbing and resilvering are I/O-intensive operations, ZFS only allows`
			`one at a time.`
			`If a scrub is paused, the`
			`.Nm zpool Cm scrub`
			`resumes it.`
			`If a resilver is in progress, ZFS does not allow a scrub to be started until the`
			`resilver completes.`
			`.Pp`
			`Note that, due to changes in pool data on a live system, it is possible for`
			`scrubs to progress slightly beyond 100% completion. During this period, no`
			`completion time estimate will be provided.`
			`.Bl -tag -width Ds`
			`.It Fl s`
			`Stop scrubbing.`
			`.El`
			`.Bl -tag -width Ds`
			`.It Fl p`
			`Pause scrubbing.`
			`Scrub pause state and progress are periodically synced to disk.`
			`If the system is restarted or pool is exported during a paused scrub,`
			`even after import, scrub will remain paused until it is resumed.`
			`Once resumed the scrub will pick up from the place where it was last`
			`checkpointed to disk.`
			`To resume a paused scrub issue`
			`.Nm zpool Cm scrub`
			`again.`
			`.It Fl w`
			`Wait until scrub has completed before returning.`
			`.El`
			`.El`
			`.Sh SEE ALSO`
			`.Xr zpool-iostat 8 ,`
			`.Xr zpool-resilver 8 ,`
			`.Xr zpool-status 8`