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https://git.proxmox.com/git/mirror_zfs.git
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35a357a9ef
Authored by: Yuri Pankov <yuri.pankov@nexenta.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: John Kennedy <john.kennedy@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: George Melikov <mail@gmelikov.ru> Ported-by: Don Brady <don.brady@intel.com> OpenZFS-issue: https://www.illumos.org/issues/6866 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/3e4fae5 Closes #5730 Porting Notes: - Omitted the illumos-specific `/dev/dsk` and `/dev/rdsk` path conversions since they don't apply on linux.
584 lines
12 KiB
Groff
584 lines
12 KiB
Groff
'\" t
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.\"
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.\" This file and its contents are supplied under the terms of the
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.\" Common Development and Distribution License ("CDDL"), version 1.0.
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.\" You may only use this file in accordance with the terms of version
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.\" 1.0 of the CDDL.
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.\"
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.\" A full copy of the text of the CDDL should have accompanied this
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.\" source. A copy of the CDDL is also available via the Internet at
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.\" http://www.illumos.org/license/CDDL.
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.\"
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.\"
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.\" Copyright 2012, Richard Lowe.
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.\" Copyright (c) 2012, 2016 by Delphix. All rights reserved.
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.\" Copyright 2016 Nexenta Systems, Inc.
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.\"
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.TH "ZDB" "8" "April 9, 2016" "" ""
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.SH "NAME"
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\fBzdb\fR - Display zpool debugging and consistency information
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.SH "SYNOPSIS"
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\fBzdb\fR [-CumdibcsDvhLMXFPAG] [-e [-p \fIpath\fR...]] [-t \fItxg\fR]
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[-U \fIcache\fR] [-I \fIinflight I/Os\fR] [-x \fIdumpdir\fR]
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[-o \fIvar\fR=\fIvalue\fR] ... [\fIpoolname\fR [\fIobject\fR ...]]
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.P
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\fBzdb\fR [-divPA] [-e [-p \fIpath\fR...]] [-U \fIcache\fR]
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\fIdataset\fR [\fIobject\fR ...]
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.P
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\fBzdb\fR -m [-MLXFPA] [-t \fItxg\fR] [-e [-p \fIpath\fR...]] [-U \fIcache\fR]
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\fIpoolname\fR [\fIvdev\fR [\fImetaslab\fR ...]]
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.P
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\fBzdb\fR -R [-A] [-e [-p \fIpath\fR...]] [-U \fIcache\fR] \fIpoolname\fR
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\fIvdev\fR:\fIoffset\fR:\fIsize\fR[:\fIflags\fR]
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.P
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\fBzdb\fR -S [-AP] [-e [-p \fIpath\fR...]] [-U \fIcache\fR] \fIpoolname\fR
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.P
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\fBzdb\fR -l [-Aqu] \fIdevice\fR
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.P
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\fBzdb\fR -C [-A] [-U \fIcache\fR]
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.SH "DESCRIPTION"
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The \fBzdb\fR utility displays information about a ZFS pool useful for
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debugging and performs some amount of consistency checking. It is a not a
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general purpose tool and options (and facilities) may change. This is neither
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a fsck(8) nor an fsdb(8) utility.
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.P
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The output of this command in general reflects the on-disk structure of a ZFS
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pool, and is inherently unstable. The precise output of most invocations is
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not documented, a knowledge of ZFS internals is assumed.
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.P
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If the \fIdataset\fR argument does not contain any \fB/\fR or \fB@\fR
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characters, it is interpreted as a pool name. The root dataset can be
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specified as \fIpool\fB/\fR (pool name followed by a slash).
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.P
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When operating on an imported and active pool it is possible, though unlikely,
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that zdb may interpret inconsistent pool data and behave erratically.
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.SH "OPTIONS"
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Display options:
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.sp
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.ne 2
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.na
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\fB-b\fR
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.ad
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.sp .6
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.RS 4n
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Display statistics regarding the number, size (logical, physical and
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allocated) and deduplication of blocks.
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.RE
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.sp
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.ne 2
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.na
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|
\fB-c\fR
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.ad
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.sp .6
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.RS 4n
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Verify the checksum of all metadata blocks while printing block statistics
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(see \fB-b\fR).
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.sp
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If specified multiple times, verify the checksums of all blocks.
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.RE
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.sp
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.ne 2
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.na
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|
\fB-C\fR
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.ad
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|
.sp .6
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.RS 4n
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Display information about the configuration. If specified with no other
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options, instead display information about the cache file
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(\fB/etc/zfs/zpool.cache\fR). To specify the cache file to display, see
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\fB-U\fR.
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.P
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If specified multiple times, and a pool name is also specified display both
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the cached configuration and the on-disk configuration. If specified multiple
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times with \fB-e\fR also display the configuration that would be used were the
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pool to be imported.
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.RE
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.sp
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.ne 2
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.na
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\fB-d\fR
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.ad
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.sp .6
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.RS 4n
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Display information about datasets. Specified once, displays basic dataset
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information: ID, create transaction, size, and object count.
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.sp
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If specified multiple times provides greater and greater verbosity.
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.sp
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If object IDs are specified, display information about those specific objects only.
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.RE
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.sp
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.ne 2
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.na
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\fB-D\fR
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.ad
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.sp .6
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.RS 4n
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Display deduplication statistics, including the deduplication ratio (dedup),
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compression ratio (compress), inflation due to the zfs copies property
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(copies), and an overall effective ratio (dedup * compress / copies).
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.sp
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If specified twice, display a histogram of deduplication statistics, showing
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the allocated (physically present on disk) and referenced (logically
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referenced in the pool) block counts and sizes by reference count.
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.sp
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If specified a third time, display the statistics independently for each deduplication table.
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.sp
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If specified a fourth time, dump the contents of the deduplication tables describing duplicate blocks.
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.sp
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If specified a fifth time, also dump the contents of the deduplication tables describing unique blocks.
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.RE
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.sp
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.ne 2
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.na
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\fB-h\fR
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.ad
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.sp .6
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.RS 4n
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Display pool history similar to \fBzpool history\fR, but include internal
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changes, transaction, and dataset information.
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.RE
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.sp
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.ne 2
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.na
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|
\fB-i\fR
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.ad
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.sp .6
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.RS 4n
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Display information about intent log (ZIL) entries relating to each
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dataset. If specified multiple times, display counts of each intent log
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transaction type.
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.RE
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|
.sp
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.ne 2
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.na
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\fB-l\fR \fIdevice\fR
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.ad
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|
.sp .6
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.RS 4n
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Read the vdev labels from the specified device. \fBzdb -l\fR will return 0 if
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valid label was found, 1 if error occured, and 2 if no valid labels were found.
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.P
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If the \fB-u\fR option is also specified, also display the uberblocks on this
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device.
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.P
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If the \fB-q\fR option is also specified, don't print the labels.
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.RE
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.sp
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.ne 2
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.na
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\fB-L\fR
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.ad
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.sp .6
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.RS 4n
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Disable leak tracing and the loading of space maps. By default, \fBzdb\fR
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verifies that all non-free blocks are referenced, which can be very expensive.
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.RE
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.sp
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.ne 2
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.na
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\fB-m\fR
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.ad
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.sp .6
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.RS 4n
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Display the offset, spacemap, and free space of each metaslab.
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When specified twice, also display information about the on-disk free
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space histogram associated with each metaslab. When specified three time,
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display the maximum contiguous free space, the in-core free space histogram,
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and the percentage of free space in each space map. When specified
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four times display every spacemap record.
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.RE
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.sp
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.ne 2
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.na
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|
\fB-M\fR
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.ad
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.sp .6
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.RS 4n
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|
Display the offset, spacemap, and free space of each metaslab.
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When specified twice, also display information about the maximum contiguous
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|
free space and the percentage of free space in each space map. When specified
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three times display every spacemap record.
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.RE
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|
.sp
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.ne 2
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.na
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|
\fB-R\fR \fIpoolname\fR \fIvdev\fR:\fIoffset\fR:\fIsize\fR[:\fIflags\fR]
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.ad
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.sp .6
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.RS 4n
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Read and display a block from the specified device. By default the block is
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displayed as a hex dump, but see the description of the \'r\' flag, below.
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.sp
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The block is specified in terms of a colon-separated tuple \fIvdev\fR (an
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integer vdev identifier) \fIoffset\fR (the offset within the vdev) \fIsize\fR
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(the size of the block to read) and, optionally, \fIflags\fR (a set of flags,
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described below).
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.sp
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.ne 2
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.na
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|
\fBb\fR \fIoffset\fR
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.ad
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|
.sp .6
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.RS 4n
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Print block pointer
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.RE
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|
.sp
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.ne 2
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.na
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|
\fBd\fR
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|
.ad
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|
.sp .6
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.RS 4n
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|
Decompress the block
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|
.RE
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|
.sp
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.ne 2
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.na
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|
\fBe\fR
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|
.ad
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|
.sp .6
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.RS 4n
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|
Byte swap the block
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.RE
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.sp
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.ne 2
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.na
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|
\fBg\fR
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.ad
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|
.sp .6
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.RS 4n
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|
Dump gang block header
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|
.RE
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|
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|
.sp
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|
.ne 2
|
|
.na
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|
\fBi\fR
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|
.ad
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|
.sp .6
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|
.RS 4n
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|
Dump indirect block
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|
.RE
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|
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|
.sp
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|
.ne 2
|
|
.na
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|
\fBr\fR
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|
.ad
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|
.sp .6
|
|
.RS 4n
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|
Dump raw uninterpreted block data
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|
.RE
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|
.RE
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|
|
|
.sp
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|
.ne 2
|
|
.na
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|
\fB-s\fR
|
|
.ad
|
|
.sp .6
|
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.RS 4n
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|
Report statistics on \fBzdb\fR\'s I/O. Display operation counts, bandwidth,
|
|
and error counts of I/O to the pool from \fBzdb\fR.
|
|
.RE
|
|
|
|
.sp
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|
.ne 2
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|
.na
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|
\fB-S\fR
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|
.ad
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|
.sp .6
|
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.RS 4n
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|
Simulate the effects of deduplication, constructing a DDT and then display
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|
that DDT as with \fB-DD\fR.
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.RE
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.sp
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.ne 2
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.na
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|
\fB-u\fR
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|
.ad
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|
.sp .6
|
|
.RS 4n
|
|
Display the current uberblock.
|
|
.RE
|
|
|
|
.P
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|
Other options:
|
|
|
|
.sp
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|
.ne 2
|
|
.na
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|
\fB-A\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Do not abort should any assertion fail.
|
|
.RE
|
|
|
|
.sp
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|
.ne 2
|
|
.na
|
|
\fB-AA\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Enable panic recovery, certain errors which would otherwise be fatal are
|
|
demoted to warnings.
|
|
.RE
|
|
|
|
.sp
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|
.ne 2
|
|
.na
|
|
\fB-AAA\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Do not abort if asserts fail and also enable panic recovery.
|
|
.RE
|
|
|
|
.sp
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|
.ne 2
|
|
.na
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|
\fB-e\fR [-p \fIpath\fR]...
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|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Operate on an exported pool, not present in \fB/etc/zfs/zpool.cache\fR. The
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|
\fB-p\fR flag specifies the path under which devices are to be searched.
|
|
.RE
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|
|
|
.sp
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|
.ne 2
|
|
.na
|
|
\fB-x\fR \fIdumpdir\fR
|
|
.ad
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|
.sp .6
|
|
.RS 4n
|
|
All blocks accessed will be copied to files in the specified directory.
|
|
The blocks will be placed in sparse files whose name is the same as
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|
that of the file or device read. zdb can be then run on the generated files.
|
|
Note that the \fB-bbc\fR flags are sufficient to access (and thus copy)
|
|
all metadata on the pool.
|
|
.RE
|
|
|
|
.sp
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|
.ne 2
|
|
.na
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|
\fB-F\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Attempt to make an unreadable pool readable by trying progressively older
|
|
transactions.
|
|
.RE
|
|
|
|
.sp
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|
.ne 2
|
|
.na
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|
\fB-G\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Dump the contents of the zfs_dbgmsg buffer before exiting zdb. zfs_dbgmsg is
|
|
a buffer used by ZFS to dump advanced debug information.
|
|
.RE
|
|
|
|
.sp
|
|
.ne 2
|
|
.na
|
|
\fB-I \fIinflight I/Os\fR \fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Limit the number of outstanding checksum I/Os to the specified value. The
|
|
default value is 200. This option affects the performance of the \fB-c\fR
|
|
option.
|
|
.RE
|
|
|
|
.sp
|
|
.ne 2
|
|
.na
|
|
\fB-o \fIvar\fR=\fIvalue\fR ... \fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Set the given global libzpool variable to the provided value. The value must
|
|
be an unsigned 32-bit integer. Currently only little-endian systems are
|
|
supported to avoid accidentally setting the high 32 bits of 64-bit variables.
|
|
.RE
|
|
|
|
.sp
|
|
.ne 2
|
|
.na
|
|
\fB-P\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Print numbers in an unscaled form more amenable to parsing, eg. 1000000 rather
|
|
than 1M.
|
|
.RE
|
|
|
|
.sp
|
|
.ne 2
|
|
.na
|
|
\fB-t\fR \fItransaction\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Specify the highest transaction to use when searching for uberblocks. See also
|
|
the \fB-u\fR and \fB-l\fR options for a means to see the available uberblocks
|
|
and their associated transaction numbers.
|
|
.RE
|
|
|
|
.sp
|
|
.ne 2
|
|
.na
|
|
\fB-U\fR \fIcachefile\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Use a cache file other than \fB/etc/zfs/zpool.cache\fR.
|
|
.RE
|
|
|
|
.sp
|
|
.ne 2
|
|
.na
|
|
\fB-v\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Enable verbosity. Specify multiple times for increased verbosity.
|
|
.RE
|
|
|
|
.sp
|
|
.ne 2
|
|
.na
|
|
\fB-X\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Attempt \'extreme\' transaction rewind, that is attempt the same recovery as
|
|
\fB-F\fR but read transactions otherwise deemed too old.
|
|
.RE
|
|
|
|
.sp
|
|
.ne 2
|
|
.na
|
|
\fB-V\fR
|
|
.ad
|
|
.sp .6
|
|
.RS 4n
|
|
Attempt a verbatim import. This mimics the behavior of the kernel when loading
|
|
a pool from a cachefile.
|
|
.RE
|
|
|
|
.P
|
|
Specifying a display option more than once enables verbosity for only that
|
|
option, with more occurrences enabling more verbosity.
|
|
.P
|
|
If no options are specified, all information about the named pool will be
|
|
displayed at default verbosity.
|
|
|
|
.SH "EXAMPLES"
|
|
.LP
|
|
\fBExample 1 \fRDisplay the configuration of imported pool 'rpool'
|
|
.sp
|
|
.in +2
|
|
.nf
|
|
# zdb -C rpool
|
|
|
|
MOS Configuration:
|
|
version: 28
|
|
name: 'rpool'
|
|
...
|
|
.fi
|
|
.in -2
|
|
.sp
|
|
|
|
.LP
|
|
\fBExample 2 \fRDisplay basic dataset information about 'rpool'
|
|
.sp
|
|
.in +2
|
|
.nf
|
|
# zdb -d rpool
|
|
Dataset mos [META], ID 0, cr_txg 4, 26.9M, 1051 objects
|
|
Dataset rpool/swap [ZVOL], ID 59, cr_txg 356, 486M, 2 objects
|
|
...
|
|
.fi
|
|
.in -2
|
|
.sp
|
|
|
|
.LP
|
|
\fBExample 3 \fRDisplay basic information about object 0
|
|
in 'rpool/export/home'
|
|
.sp
|
|
.in +2
|
|
.nf
|
|
# zdb -d rpool/export/home 0
|
|
Dataset rpool/export/home [ZPL], ID 137, cr_txg 1546, 32K, 8 objects
|
|
|
|
Object lvl iblk dblk dsize lsize %full type
|
|
0 7 16K 16K 15.0K 16K 25.00 DMU dnode
|
|
.fi
|
|
.in -2
|
|
.sp
|
|
|
|
.LP
|
|
\fBExample 4 \fRDisplay the predicted effect of enabling deduplication on 'rpool'
|
|
.sp
|
|
.in +2
|
|
.nf
|
|
# zdb -S rpool
|
|
Simulated DDT histogram:
|
|
|
|
bucket allocated referenced
|
|
______ ______________________________ ______________________________
|
|
refcnt blocks LSIZE PSIZE DSIZE blocks LSIZE PSIZE DSIZE
|
|
------ ------ ----- ----- ----- ------ ----- ----- -----
|
|
1 694K 27.1G 15.0G 15.0G 694K 27.1G 15.0G 15.0G
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|
2 35.0K 1.33G 699M 699M 74.7K 2.79G 1.45G 1.45G
|
|
...
|
|
dedup = 1.11, compress = 1.80, copies = 1.00, dedup * compress / copies = 2.00
|
|
.fi
|
|
.in -2
|
|
.sp
|
|
|
|
.SH "ENVIRONMENT VARIABLES"
|
|
.TP
|
|
.B "SPA_CONFIG_PATH"
|
|
Override the default \fBspa_config_path\fR (\fI/etc/zfs/zpool.cache\fR) setting. If \fB-U\fR flag is specified it will override this environment variable settings once again.
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|
|
|
.SH "SEE ALSO"
|
|
zfs(8), zpool(8)
|