mirror of
https://github.com/openzfs/zfs.git
synced 2025-10-01 11:26:49 +00:00
26983d6fa7
When attempting to debug performance problems on large systems, one of the major factors that affect performance is free space fragmentation. This heavily affects the allocation process, which is an area of active development in ZFS. Unfortunately, fragmenting a large pool for testing purposes is time consuming; it usually involves filling the pool and then repeatedly overwriting data until the free space becomes fragmented, which can take many hours. And even if the time is available, artificial workloads rarely generate the same fragmentation patterns as the natural workloads they're attempting to mimic. This patch has two parts. First, in zdb, we add the ability to export the full allocation map of the pool. It iterates over each vdev, printing every allocated segment in the ms_allocatable range tree. This can be done while the pool is online, though in that case the allocation map may actually be from several different TXGs as new ones are loaded on demand. The second is a new subcommand for zhack, zhack metaslab leak (and its supporting kernel changes). This is a zhack subcommand that imports a pool and then modified the range trees of the metaslabs, allowing the sync process to write them out normall. It does not currently store those allocations anywhere to make them reversible, and there is no corresponding free subcommand (which would be extremely dangerous); this is an irreversible process, only intended for performance testing. The only way to reclaim the space afterwards is to destroy the pool or roll back to a checkpoint. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Paul Dagnelie <paul.dagnelie@klarasystems.com> Sponsored-by: Klara, Inc. Sponsored-by: Wasabi Technology, Inc. Closes #17576
603 lines
18 KiB
Groff
603 lines
18 KiB
Groff
.\" SPDX-License-Identifier: CDDL-1.0
|
|
.\"
|
|
.\" This file and its contents are supplied under the terms of the
|
|
.\" Common Development and Distribution License ("CDDL"), version 1.0.
|
|
.\" You may only use this file in accordance with the terms of version
|
|
.\" 1.0 of the CDDL.
|
|
.\"
|
|
.\" A full copy of the text of the CDDL should have accompanied this
|
|
.\" source. A copy of the CDDL is also available via the Internet at
|
|
.\" http://www.illumos.org/license/CDDL.
|
|
.\"
|
|
.\" Copyright 2012, Richard Lowe.
|
|
.\" Copyright (c) 2012, 2019 by Delphix. All rights reserved.
|
|
.\" Copyright 2017 Nexenta Systems, Inc.
|
|
.\" Copyright (c) 2017 Lawrence Livermore National Security, LLC.
|
|
.\" Copyright (c) 2017 Intel Corporation.
|
|
.\"
|
|
.Dd August 12, 2025
|
|
.Dt ZDB 8
|
|
.Os
|
|
.
|
|
.Sh NAME
|
|
.Nm zdb
|
|
.Nd display ZFS storage pool debugging and consistency information
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl AbcdDFGhikLMNPsTvXYy
|
|
.Op Fl e Oo Fl V Oc Oo Fl p Ar path Oc Ns …
|
|
.Op Fl I Ar inflight-I/O-ops
|
|
.Oo Fl o Ar var Ns = Ns Ar value Oc Ns …
|
|
.Op Fl t Ar txg
|
|
.Op Fl U Ar cache
|
|
.Op Fl x Ar dumpdir
|
|
.Op Fl K Ar key
|
|
.Op Ar poolname Ns Op / Ns Ar dataset Ns | Ns Ar objset-ID
|
|
.Op Ar object Ns | Ns Ar range Ns …
|
|
.Nm
|
|
.Op Fl AdiPv
|
|
.Op Fl e Oo Fl V Oc Oo Fl p Ar path Oc Ns …
|
|
.Op Fl U Ar cache
|
|
.Op Fl K Ar key
|
|
.Ar poolname Ns Op Ar / Ns Ar dataset Ns | Ns Ar objset-ID
|
|
.Op Ar object Ns | Ns Ar range Ns …
|
|
.Nm
|
|
.Fl B
|
|
.Op Fl e Oo Fl V Oc Oo Fl p Ar path Oc Ns …
|
|
.Op Fl U Ar cache
|
|
.Op Fl K Ar key
|
|
.Ar poolname Ns Ar / Ns Ar objset-ID
|
|
.Op Ar backup-flags
|
|
.Nm
|
|
.Fl C
|
|
.Op Fl A
|
|
.Op Fl U Ar cache
|
|
.Op Ar poolname
|
|
.Nm
|
|
.Fl E
|
|
.Op Fl A
|
|
.Ar word0 : Ns Ar word1 Ns :…: Ns Ar word15
|
|
.Nm
|
|
.Fl l
|
|
.Op Fl Aqu
|
|
.Ar device
|
|
.Nm
|
|
.Fl m
|
|
.Op Fl AFLPXY
|
|
.Op Fl e Oo Fl V Oc Oo Fl p Ar path Oc Ns …
|
|
.Op Fl t Ar txg
|
|
.Op Fl U Ar cache
|
|
.Ar poolname Op Ar vdev Oo Ar metaslab Oc Ns …
|
|
.Nm
|
|
.Fl -allocated-map
|
|
.Op Fl mAFLPXY
|
|
.Op Fl e Oo Fl V Oc Oo Fl p Ar path Oc Ns …
|
|
.Op Fl t Ar txg
|
|
.Op Fl U Ar cache
|
|
.Ar poolname Op Ar vdev Oo Ar metaslab Oc Ns …
|
|
.Nm
|
|
.Fl O
|
|
.Op Fl K Ar key
|
|
.Ar dataset path
|
|
.Nm
|
|
.Fl r
|
|
.Op Fl K Ar key
|
|
.Ar dataset path destination
|
|
.Nm
|
|
.Fl R
|
|
.Op Fl A
|
|
.Op Fl e Oo Fl V Oc Oo Fl p Ar path Oc Ns …
|
|
.Op Fl U Ar cache
|
|
.Ar poolname vdev : Ns Ar offset : Ns Oo Ar lsize Ns / Oc Ns Ar psize Ns Op : Ns Ar flags
|
|
.Nm
|
|
.Fl S
|
|
.Op Fl AP
|
|
.Op Fl e Oo Fl V Oc Oo Fl p Ar path Oc Ns …
|
|
.Op Fl U Ar cache
|
|
.Ar poolname
|
|
.
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
utility displays information about a ZFS pool useful for debugging and performs
|
|
some amount of consistency checking.
|
|
It is a not a general purpose tool and options
|
|
.Pq and facilities
|
|
may change.
|
|
It is not a
|
|
.Xr fsck 8
|
|
utility.
|
|
.Pp
|
|
The output of this command in general reflects the on-disk structure of a ZFS
|
|
pool, and is inherently unstable.
|
|
The precise output of most invocations is not documented, a knowledge of ZFS
|
|
internals is assumed.
|
|
.Pp
|
|
If the
|
|
.Ar dataset
|
|
argument does not contain any
|
|
.Qq Sy /
|
|
or
|
|
.Qq Sy @
|
|
characters, it is interpreted as a pool name.
|
|
The root dataset can be specified as
|
|
.Qq Ar pool Ns / .
|
|
.Pp
|
|
.Nm
|
|
is an
|
|
.Qq offline
|
|
tool; it accesses the block devices underneath the pools directly from
|
|
userspace and does not care if the pool is imported or datasets are mounted
|
|
(or even if the system understands ZFS at all).
|
|
When operating on an imported and active pool it is possible, though unlikely,
|
|
that zdb may interpret inconsistent pool data and behave erratically.
|
|
.
|
|
.Sh OPTIONS
|
|
Display options:
|
|
.Bl -tag -width Ds
|
|
.It Fl Sy -allocated-map
|
|
Prints out a list of all the allocated regions in the pool.
|
|
Primarily intended for use with the
|
|
.Nm zhack metaslab leak
|
|
subcommand.
|
|
.It Fl b , -block-stats
|
|
Display statistics regarding the number, size
|
|
.Pq logical, physical and allocated
|
|
and deduplication of blocks.
|
|
.It Fl B , -backup
|
|
Generate a backup stream, similar to
|
|
.Nm zfs Cm send ,
|
|
but for the numeric objset ID, and without opening the dataset.
|
|
This can be useful in recovery scenarios if dataset metadata has become
|
|
corrupted but the dataset itself is readable.
|
|
The optional
|
|
.Ar flags
|
|
argument is a string of one or more of the letters
|
|
.Sy e ,
|
|
.Sy L ,
|
|
.Sy c ,
|
|
and
|
|
.Sy w ,
|
|
which correspond to the same flags in
|
|
.Xr zfs-send 8 .
|
|
.It Fl c , -checksum
|
|
Verify the checksum of all metadata blocks while printing block statistics
|
|
.Po see
|
|
.Fl b
|
|
.Pc .
|
|
.Pp
|
|
If specified multiple times, verify the checksums of all blocks.
|
|
.It Fl C , -config
|
|
Display information about the configuration.
|
|
If specified with no other options, instead display information about the cache
|
|
file
|
|
.Pq Pa /etc/zfs/zpool.cache .
|
|
To specify the cache file to display, see
|
|
.Fl U .
|
|
.Pp
|
|
If specified multiple times, and a pool name is also specified display both the
|
|
cached configuration and the on-disk configuration.
|
|
If specified multiple times with
|
|
.Fl e
|
|
also display the configuration that would be used were the pool to be imported.
|
|
.It Fl d , -datasets
|
|
Display information about datasets.
|
|
Specified once, displays basic dataset information: ID, create transaction,
|
|
size, and object count.
|
|
See
|
|
.Fl N
|
|
for determining if
|
|
.Ar poolname Ns Op / Ns Ar dataset Ns | Ns Ar objset-ID
|
|
is to use the specified
|
|
.Ar dataset Ns | Ns Ar objset-ID
|
|
as a string (dataset name) or a number (objset ID) when
|
|
datasets have numeric names.
|
|
.Pp
|
|
If specified multiple times provides greater and greater verbosity.
|
|
.Pp
|
|
If object IDs or object ID ranges are specified, display information about
|
|
those specific objects or ranges only.
|
|
.Pp
|
|
An object ID range is specified in terms of a colon-separated tuple of
|
|
the form
|
|
.Ao start Ac : Ns Ao end Ac Ns Op : Ns Ao flags Ac .
|
|
The fields
|
|
.Ar start
|
|
and
|
|
.Ar end
|
|
are integer object identifiers that denote the upper and lower bounds
|
|
of the range.
|
|
An
|
|
.Ar end
|
|
value of -1 specifies a range with no upper bound.
|
|
The
|
|
.Ar flags
|
|
field optionally specifies a set of flags, described below, that control
|
|
which object types are dumped.
|
|
By default, all object types are dumped.
|
|
A minus sign
|
|
.Pq -
|
|
negates the effect of the flag that follows it and has no effect unless
|
|
preceded by the
|
|
.Ar A
|
|
flag.
|
|
For example, the range 0:-1:A-d will dump all object types except for
|
|
directories.
|
|
.Pp
|
|
.Bl -tag -compact -width Ds
|
|
.It Sy A
|
|
Dump all objects (this is the default)
|
|
.It Sy d
|
|
Dump ZFS directory objects
|
|
.It Sy f
|
|
Dump ZFS plain file objects
|
|
.It Sy m
|
|
Dump SPA space map objects
|
|
.It Sy z
|
|
Dump ZAP objects
|
|
.It Sy -
|
|
Negate the effect of next flag
|
|
.El
|
|
.It Fl D , -dedup-stats
|
|
Display deduplication statistics, including the deduplication ratio
|
|
.Pq Sy dedup ,
|
|
compression ratio
|
|
.Pq Sy compress ,
|
|
inflation due to the zfs copies property
|
|
.Pq Sy copies ,
|
|
and an overall effective ratio
|
|
.Pq Sy dedup No \(mu Sy compress No / Sy copies .
|
|
.It Fl DD
|
|
Display a histogram of deduplication statistics, showing the allocated
|
|
.Pq physically present on disk
|
|
and referenced
|
|
.Pq logically referenced in the pool
|
|
block counts and sizes by reference count.
|
|
.It Fl DDD
|
|
Display the statistics independently for each deduplication table.
|
|
.It Fl DDDD
|
|
Dump the contents of the deduplication tables describing duplicate blocks.
|
|
.It Fl DDDDD
|
|
Also dump the contents of the deduplication tables describing unique blocks.
|
|
.It Fl E , -embedded-block-pointer Ns = Ns Ar word0 : Ns Ar word1 Ns :…: Ns Ar word15
|
|
Decode and display block from an embedded block pointer specified by the
|
|
.Ar word
|
|
arguments.
|
|
.It Fl h , -history
|
|
Display pool history similar to
|
|
.Nm zpool Cm history ,
|
|
but include internal changes, transaction, and dataset information.
|
|
.It Fl i , -intent-logs
|
|
Display information about intent log
|
|
.Pq ZIL
|
|
entries relating to each dataset.
|
|
If specified multiple times, display counts of each intent log transaction type.
|
|
.It Fl k , -checkpointed-state
|
|
Examine the checkpointed state of the pool.
|
|
Note, the on disk format of the pool is not reverted to the checkpointed state.
|
|
.It Fl l , -label Ns = Ns Ar device
|
|
Read the vdev labels and L2ARC header from the specified device.
|
|
.Nm Fl l
|
|
will return 0 if valid label was found, 1 if error occurred, and 2 if no valid
|
|
labels were found.
|
|
The presence of L2ARC header is indicated by a specific
|
|
sequence (L2ARC_DEV_HDR_MAGIC).
|
|
If there is an accounting error in the size or the number of L2ARC log blocks
|
|
.Nm Fl l
|
|
will return 1.
|
|
Each unique configuration is displayed only once.
|
|
.It Fl ll Ar device
|
|
In addition display label space usage stats.
|
|
If a valid L2ARC header was found
|
|
also display the properties of log blocks used for restoring L2ARC contents
|
|
(persistent L2ARC).
|
|
.It Fl lll Ar device
|
|
Display every configuration, unique or not.
|
|
If a valid L2ARC header was found
|
|
also display the properties of log entries in log blocks used for restoring
|
|
L2ARC contents (persistent L2ARC).
|
|
.Pp
|
|
If the
|
|
.Fl q
|
|
option is also specified, don't print the labels or the L2ARC header.
|
|
.Pp
|
|
If the
|
|
.Fl u
|
|
option is also specified, also display the uberblocks on this device.
|
|
Specify multiple times to increase verbosity.
|
|
.It Fl L , -disable-leak-tracking
|
|
Disable leak detection and the loading of space maps.
|
|
By default,
|
|
.Nm
|
|
verifies that all non-free blocks are referenced, which can be very expensive.
|
|
.It Fl m , -metaslabs
|
|
Display the offset, spacemap, free space of each metaslab, all the log
|
|
spacemaps and their obsolete entry statistics.
|
|
.It Fl mm
|
|
Also display information about the on-disk free space histogram associated with
|
|
each metaslab.
|
|
.It Fl mmm
|
|
Display the maximum contiguous free space, the in-core free space histogram, and
|
|
the percentage of free space in each space map.
|
|
.It Fl mmmm
|
|
Display every spacemap record.
|
|
.It Fl M , -metaslab-groups
|
|
Display all "normal" vdev metaslab group information - per-vdev metaslab count,
|
|
fragmentation,
|
|
and free space histogram, as well as overall pool fragmentation and histogram.
|
|
.It Fl MM
|
|
"Special" vdevs are added to -M's normal output.
|
|
Also display information about the maximum contiguous free space and the
|
|
percentage of free space in each space map.
|
|
.It Fl MMM
|
|
Display every spacemap record.
|
|
.It Fl N
|
|
Same as
|
|
.Fl d
|
|
but force zdb to interpret the
|
|
.Op Ar dataset Ns | Ns Ar objset-ID
|
|
in
|
|
.Op Ar poolname Ns Op / Ns Ar dataset Ns | Ns Ar objset-ID
|
|
as a numeric objset ID.
|
|
.It Fl O , -object-lookups Ns = Ns Ar dataset path
|
|
Look up the specified
|
|
.Ar path
|
|
inside of the
|
|
.Ar dataset
|
|
and display its metadata and indirect blocks.
|
|
Specified
|
|
.Ar path
|
|
must be relative to the root of
|
|
.Ar dataset .
|
|
This option can be combined with
|
|
.Fl v
|
|
for increasing verbosity.
|
|
.It Fl r , -copy-object Ns = Ns Ar dataset path destination
|
|
Copy the specified
|
|
.Ar path
|
|
inside of the
|
|
.Ar dataset
|
|
to the specified destination.
|
|
Specified
|
|
.Ar path
|
|
must be relative to the root of
|
|
.Ar dataset .
|
|
This option can be combined with
|
|
.Fl v
|
|
for increasing verbosity.
|
|
.It Xo
|
|
.Fl R , -read-block Ns = Ns Ar poolname vdev : Ns Ar offset : Ns Oo Ar lsize Ns / Oc Ns Ar psize Ns Op : Ns Ar flags
|
|
.Xc
|
|
Read and display a block from the specified device.
|
|
By default the block is displayed as a hex dump, but see the description of the
|
|
.Sy r
|
|
flag, below.
|
|
.Pp
|
|
The block is specified in terms of a colon-separated tuple
|
|
.Ar vdev
|
|
.Pq an integer vdev identifier
|
|
.Ar offset
|
|
.Pq the offset within the vdev
|
|
.Ar size
|
|
.Pq the physical size, or logical size / physical size
|
|
of the block to read and, optionally,
|
|
.Ar flags
|
|
.Pq a set of flags, described below .
|
|
.Pp
|
|
.Bl -tag -compact -width "b offset"
|
|
.It Sy b Ar offset
|
|
Print block pointer at hex offset
|
|
.It Sy c
|
|
Calculate and display checksums
|
|
.It Sy d
|
|
Decompress the block.
|
|
Set environment variable
|
|
.Nm ZDB_NO_ZLE
|
|
to skip zle when guessing.
|
|
.It Sy e
|
|
Byte swap the block
|
|
.It Sy g
|
|
Dump gang block header
|
|
.It Sy i
|
|
Dump indirect block
|
|
.It Sy r
|
|
Dump raw uninterpreted block data
|
|
.It Sy v
|
|
Verbose output for guessing compression algorithm
|
|
.El
|
|
.It Fl s , -io-stats
|
|
Report statistics on
|
|
.Nm zdb
|
|
I/O.
|
|
Display operation counts, bandwidth, and error counts of I/O to the pool from
|
|
.Nm .
|
|
.It Fl S , -simulate-dedup
|
|
Simulate the effects of deduplication, constructing a DDT and then display
|
|
that DDT as with
|
|
.Fl DD .
|
|
.It Fl T , -brt-stats
|
|
Display block reference table (BRT) statistics, including the size of uniques
|
|
blocks cloned, the space saving as a result of cloning, and the saving ratio.
|
|
.It Fl TT
|
|
Display the per-vdev BRT statistics, including total references.
|
|
.It Fl TTT
|
|
Display histograms of per-vdev BRT refcounts.
|
|
.It Fl TTTT
|
|
Dump the contents of the block reference tables.
|
|
.It Fl u , -uberblock
|
|
Display the current uberblock.
|
|
.El
|
|
.Pp
|
|
Other options:
|
|
.Bl -tag -width Ds
|
|
.It Fl A , -ignore-assertions
|
|
Do not abort should any assertion fail.
|
|
.It Fl AA
|
|
Enable panic recovery, certain errors which would otherwise be fatal are
|
|
demoted to warnings.
|
|
.It Fl AAA
|
|
Do not abort if asserts fail and also enable panic recovery.
|
|
.It Fl e , -exported Ns = Ns Oo Fl p Ar path Oc Ns …
|
|
Operate on an exported pool, not present in
|
|
.Pa /etc/zfs/zpool.cache .
|
|
The
|
|
.Fl p
|
|
flag specifies the path under which devices are to be searched.
|
|
.It Fl x , -dump-blocks Ns = Ns Ar dumpdir
|
|
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
|
|
that of the file or device read.
|
|
.Nm
|
|
can be then run on the generated files.
|
|
Note that the
|
|
.Fl bbc
|
|
flags are sufficient to access
|
|
.Pq and thus copy
|
|
all metadata on the pool.
|
|
.It Fl F , -automatic-rewind
|
|
Attempt to make an unreadable pool readable by trying progressively older
|
|
transactions.
|
|
.It Fl G , -dump-debug-msg
|
|
Dump the contents of the zfs_dbgmsg buffer before exiting
|
|
.Nm .
|
|
zfs_dbgmsg is a buffer used by ZFS to dump advanced debug information.
|
|
.It Fl I , -inflight Ns = Ns Ar inflight-I/O-ops
|
|
Limit the number of outstanding checksum I/O operations to the specified value.
|
|
The default value is 200.
|
|
This option affects the performance of the
|
|
.Fl c
|
|
option.
|
|
.It Fl K , -key Ns = Ns Ar key
|
|
Decryption key needed to access an encrypted dataset.
|
|
This will cause
|
|
.Nm
|
|
to attempt to unlock the dataset using the encryption root, key format and other
|
|
encryption parameters on the given dataset.
|
|
.Nm
|
|
can still inspect pool and dataset structures on encrypted datasets without
|
|
unlocking them, but will not be able to access file names and attributes and
|
|
object contents. \fBWARNING:\fP The raw decryption key and any decrypted data
|
|
will be in user memory while
|
|
.Nm
|
|
is running.
|
|
Other user programs may be able to extract it by inspecting
|
|
.Nm
|
|
as it runs.
|
|
Exercise extreme caution when using this option in shared or uncontrolled
|
|
environments.
|
|
.It Fl o , -option Ns = Ns Ar var Ns = Ns Ar value Ns …
|
|
Set the given tunable to the provided value.
|
|
.It Fl o , -option Ns = Ns Ar var Ns …
|
|
Show the value of the given tunable.
|
|
.It Fl o , -option Ns = Ns show
|
|
Show all tunables and their values.
|
|
.It Fl o , -option Ns = Ns info Ns = Ns Ar value Ns …
|
|
Show info about a tunable, including their name, type and description.
|
|
.It Fl o , -option Ns = Ns info
|
|
Show info about all tunables.
|
|
.It Fl P , -parseable
|
|
Print numbers in an unscaled form more amenable to parsing, e.g.\&
|
|
.Sy 1000000
|
|
rather than
|
|
.Sy 1M .
|
|
.It Fl t , -txg Ns = Ns Ar transaction
|
|
Specify the highest transaction to use when searching for uberblocks.
|
|
See also the
|
|
.Fl u
|
|
and
|
|
.Fl l
|
|
options for a means to see the available uberblocks and their associated
|
|
transaction numbers.
|
|
.It Fl U , -cachefile Ns = Ns Ar cachefile
|
|
Use a cache file other than
|
|
.Pa /etc/zfs/zpool.cache .
|
|
.It Fl v , -verbose
|
|
Enable verbosity.
|
|
Specify multiple times for increased verbosity.
|
|
.It Fl V , -verbatim
|
|
Attempt verbatim import.
|
|
This mimics the behavior of the kernel when loading a pool from a cachefile.
|
|
Only usable with
|
|
.Fl e .
|
|
.It Fl X , -extreme-rewind
|
|
Attempt
|
|
.Qq extreme
|
|
transaction rewind, that is attempt the same recovery as
|
|
.Fl F
|
|
but read transactions otherwise deemed too old.
|
|
.It Fl Y , -all-reconstruction
|
|
Attempt all possible combinations when reconstructing indirect split blocks.
|
|
This flag disables the individual I/O deadman timer in order to allow as
|
|
much time as required for the attempted reconstruction.
|
|
.It Fl y , -livelist
|
|
Perform validation for livelists that are being deleted.
|
|
Scans through the livelist and metaslabs, checking for duplicate entries
|
|
and compares the two, checking for potential double frees.
|
|
If it encounters issues, warnings will be printed, but the command will not
|
|
necessarily fail.
|
|
.El
|
|
.Pp
|
|
Specifying a display option more than once enables verbosity for only that
|
|
option, with more occurrences enabling more verbosity.
|
|
.Pp
|
|
If no options are specified, all information about the named pool will be
|
|
displayed at default verbosity.
|
|
.
|
|
.Sh EXIT STATUS
|
|
The
|
|
.Nm
|
|
utility exits
|
|
.Sy 0
|
|
on success,
|
|
.Sy 1
|
|
if a fatal error occurs,
|
|
.Sy 2
|
|
if invalid command line options were specified, or
|
|
.Sy 3
|
|
if on-disk corruption was detected, but was not fatal.
|
|
.Sh EXAMPLES
|
|
.Ss Example 1 : No Display the configuration of imported pool Ar rpool
|
|
.Bd -literal
|
|
.No # Nm zdb Fl C Ar rpool
|
|
MOS Configuration:
|
|
version: 28
|
|
name: 'rpool'
|
|
…
|
|
.Ed
|
|
.
|
|
.Ss Example 2 : No Display basic dataset information about Ar rpool
|
|
.Bd -literal
|
|
.No # Nm zdb Fl d Ar 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
|
|
…
|
|
.Ed
|
|
.
|
|
.Ss Example 3 : No Display basic information about object 0 in Ar rpool/export/home
|
|
.Bd -literal
|
|
.No # Nm zdb Fl d Ar 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
|
|
.Ed
|
|
.
|
|
.Ss Example 4 : No Display the predicted effect of enabling deduplication on Ar rpool
|
|
.Bd -literal
|
|
.No # Nm zdb Fl S Ar 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
|
|
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
|
|
.Ed
|
|
.
|
|
.Sh SEE ALSO
|
|
.Xr zfs 8 ,
|
|
.Xr zpool 8
|