cmd/zpool/zpool.8

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.Dd July 26, 2014
.Dt ZPOOL 8
.Os
.Sh NAME
.Nm zpool
.Nd configures ZFS storage pools
.Sh SYNOPSIS
.Nm
.Op Fl \&?
.Nm
.Cm add
.Op Fl fn
.Ar pool vdev ...
.Nm
.Cm attach
.Op Fl f
.Ar pool device new_device
.Nm
.Cm clear
.Op Fl F Op Fl n
.Ar pool
.Op Ar device
.Nm
.Cm create
.Op Fl fnd
.Op Fl o Ar property Ns = Ns Ar value
.Ar ...
.Op Fl O Ar file-system-property Ns = Ns Ar value
.Ar ...
.Op Fl m Ar mountpoint
.Op Fl R Ar root
.Ar pool vdev ...
.Nm
.Cm destroy
.Op Fl f
.Ar pool
.Nm
.Cm detach
.Ar pool device
.Nm
.Cm export
.Op Fl f
.Ar pool ...
.Nm
.Cm get
.Op Fl Hp
.Op Fl o Ar field Ns Op , Ns Ar ...
.Ar all | property Ns Op , Ns Ar ...
.Ar pool ...
.Nm
.Cm history
.Op Fl il
.Op Ar pool
.Ar ...
.Nm
.Cm import
.Op Fl d Ar dir | Fl c Ar cachefile
.Op Fl D
.Nm
.Cm import
.Op Fl o Ar mntopts
.Op Fl o Ar property Ns = Ns Ar value
.Ar ...
.Op Fl d Ar dir | Fl c Ar cachefile
.Op Fl D
.Op Fl f
.Op Fl m
.Op Fl N
.Op Fl R Ar root
.Op Fl F Op Fl n
.Fl a
.Nm
.Cm import
.Op Fl o Ar mntopts
.Op Fl o Ar property Ns = Ns Ar value
.Ar ...
.Op Fl d Ar dir | Fl c Ar cachefile
.Op Fl D
.Op Fl f
.Op Fl m
.Op Fl N
.Op Fl R Ar root
.Op Fl F Op Fl n
.Ar pool | id
.Op Ar newpool
.Nm
.Cm iostat
.Op Fl T Cm d Ns | Ns Cm u
.Op Fl v
.Op Ar pool
.Ar ...
.Nm
.Cm labelclear
.Op Fl f
.Ar device
.Nm
.Cm list
.Op Fl Hpv
.Op Fl o Ar property Ns Op , Ns Ar ...
.Op Fl T Cm d Ns | Ns Cm u
.Op Ar pool
.Ar ...
.Op Ar inverval Op Ar count
.Nm
.Cm offline
.Op Fl t
.Ar pool device ...
.Nm
.Cm online
.Op Fl e
.Ar pool device ...
.Nm
.Cm reguid
.Ar pool
.Nm
.Cm remove
.Ar pool device ...
.Nm
.Cm reopen
.Ar pool
.Nm
.Cm replace
.Op Fl f
.Ar pool device
.Op Ar new_device
.Nm
.Cm scrub
.Op Fl s
.Ar pool ...
.Nm
.Cm set
.Ar property Ns = Ns Ar value pool
.Nm
.Cm split
.Op Fl n
.Op Fl R Ar altroot
.Op Fl o Ar mntopts
.Op Fl o Ar property Ns = Ns Ar value
.Ar pool newpool
.Op Ar device ...
.Nm
.Cm status
.Op Fl vx
.Op Fl T Cm d Ns | Ns Cm u
.Op Ar pool
.Ar ...
.Op Ar interval Op Ar count
.Nm
.Cm upgrade
.Op Fl v
.Nm
.Cm upgrade
.Op Fl V Ar version
.Fl a | Ar pool ...
.Sh DESCRIPTION
The
.Nm
command configures
.Tn ZFS
storage pools. A storage pool is a collection of devices that provides physical
storage and data replication for
.Tn ZFS
datasets.
.Pp
All datasets within a storage pool share the same space. See
.Xr zfs 8
for information on managing datasets.
.Ss Virtual Devices (vdevs)
A
.Qq virtual device
.Pq No vdev
describes a single device or a collection of devices organized according to
certain performance and fault characteristics. The following virtual devices
are supported:
.Bl -tag -width "XXXXXX"
.It Sy disk
A block device, typically located under
.Pa /dev .
.Tn ZFS
can use individual slices or partitions, though the recommended mode of
operation is to use whole disks. A disk can be specified by a full path to the
device or the
.Xr geom 4
provider name. When given a whole disk,
.Tn ZFS
automatically labels the disk, if necessary.
.It Sy file
A regular file. The use of files as a backing store is strongly discouraged. It
is designed primarily for experimental purposes, as the fault tolerance of a
file is only as good the file system of which it is a part. A file must be
specified by a full path.
.It Sy mirror
A mirror of two or more devices. Data is replicated in an identical fashion
across all components of a mirror. A mirror with
.Em N
disks of size
.Em X
can hold
.Em X
bytes and can withstand
.Pq Em N-1
devices failing before data integrity is compromised.
.It Sy raidz
(or
.Sy raidz1 raidz2 raidz3 ) .
A variation on
.Sy RAID-5
that allows for better distribution of parity and eliminates the
.Qq Sy RAID-5
write hole (in which data and parity become inconsistent after a power loss).
Data and parity is striped across all disks within a
.No raidz
group.
.Pp
A
.No raidz
group can have single-, double- , or triple parity, meaning that the
.No raidz
group can sustain one, two, or three failures, respectively, without
losing any data. The
.Sy raidz1 No vdev
type specifies a single-parity
.No raidz
group; the
.Sy raidz2 No vdev
type specifies a double-parity
.No raidz
group; and the
.Sy raidz3 No vdev
type specifies a triple-parity
.No raidz
group. The
.Sy raidz No vdev
type is an alias for
.Sy raidz1 .
.Pp
A
.No raidz
group with
.Em N
disks of size
.Em X
with
.Em P
parity disks can hold approximately
.Sm off
.Pq Em N-P
*X
.Sm on
bytes and can withstand
.Em P
device(s) failing before data integrity is compromised. The minimum number of
devices in a
.No raidz
group is one more than the number of parity disks. The
recommended number is between 3 and 9 to help increase performance.
.It Sy spare
A special
.No pseudo- Ns No vdev
which keeps track of available hot spares for a pool.
For more information, see the
.Qq Sx Hot Spares
section.
.It Sy log
A separate-intent log device. If more than one log device is specified, then
writes are load-balanced between devices. Log devices can be mirrored. However,
.No raidz
.No vdev
types are not supported for the intent log. For more information,
see the
.Qq Sx Intent Log
section.
.It Sy cache
A device used to cache storage pool data. A cache device cannot be configured
as a mirror or
.No raidz
group. For more information, see the
.Qq Sx Cache Devices
section.
.El
.Pp
Virtual devices cannot be nested, so a mirror or
.No raidz
virtual device can only
contain files or disks. Mirrors of mirrors (or other combinations) are not
allowed.
.Pp
A pool can have any number of virtual devices at the top of the configuration
(known as
.Qq root
.No vdev Ns s).
Data is dynamically distributed across all top-level devices to balance data
among devices. As new virtual devices are added,
.Tn ZFS
automatically places data on the newly available devices.
.Pp
Virtual devices are specified one at a time on the command line, separated by
whitespace. The keywords
.Qq mirror
and
.Qq raidz
are used to distinguish where a group ends and another begins. For example, the
following creates two root
.No vdev Ns s,
each a mirror of two disks:
.Bd -literal -offset 2n
.Li # Ic zpool create mypool mirror da0 da1 mirror da2 da3
.Ed
.Ss Device Failure and Recovery
.Tn ZFS
supports a rich set of mechanisms for handling device failure and data
corruption. All metadata and data is checksummed, and
.Tn ZFS
automatically repairs bad data from a good copy when corruption is detected.
.Pp
In order to take advantage of these features, a pool must make use of some form
of redundancy, using either mirrored or
.No raidz
groups. While
.Tn ZFS
supports running in a non-redundant configuration, where each root
.No vdev
is simply a disk or file, this is strongly discouraged. A single case of bit
corruption can render some or all of your data unavailable.
.Pp
A pool's health status is described by one of three states: online, degraded,
or faulted. An online pool has all devices operating normally. A degraded pool
is one in which one or more devices have failed, but the data is still
available due to a redundant configuration. A faulted pool has corrupted
metadata, or one or more faulted devices, and insufficient replicas to continue
functioning.
.Pp
The health of the top-level
.No vdev ,
such as mirror or
.No raidz
device, is
potentially impacted by the state of its associated
.No vdev Ns s,
or component devices. A top-level
.No vdev
or component device is in one of the following states:
.Bl -tag -width "DEGRADED"
.It Sy DEGRADED
One or more top-level
.No vdev Ns s
is in the degraded state because one or more
component devices are offline. Sufficient replicas exist to continue
functioning.
.Pp
One or more component devices is in the degraded or faulted state, but
sufficient replicas exist to continue functioning. The underlying conditions
are as follows:
.Bl -bullet -offset 2n
.It
The number of checksum errors exceeds acceptable levels and the device is
degraded as an indication that something may be wrong.
.Tn ZFS
continues to use the device as necessary.
.It
The number of
.Tn I/O
errors exceeds acceptable levels. The device could not be
marked as faulted because there are insufficient replicas to continue
functioning.
.El
.It Sy FAULTED
One or more top-level
.No vdev Ns s
is in the faulted state because one or more
component devices are offline. Insufficient replicas exist to continue
functioning.
.Pp
One or more component devices is in the faulted state, and insufficient
replicas exist to continue functioning. The underlying conditions are as
follows:
.Bl -bullet -offset 2n
.It
The device could be opened, but the contents did not match expected values.
.It
The number of
.Tn I/O
errors exceeds acceptable levels and the device is faulted to
prevent further use of the device.
.El
.It Sy OFFLINE
The device was explicitly taken offline by the
.Qq Nm Cm offline
command.
.It Sy ONLINE
The device is online and functioning.
.It Sy REMOVED
The device was physically removed while the system was running. Device removal
detection is hardware-dependent and may not be supported on all platforms.
.It Sy UNAVAIL
The device could not be opened. If a pool is imported when a device was
unavailable, then the device will be identified by a unique identifier instead
of its path since the path was never correct in the first place.
.El
.Pp
If a device is removed and later reattached to the system,
.Tn ZFS
attempts to put the device online automatically. Device attach detection is
hardware-dependent and might not be supported on all platforms.
.Ss Hot Spares
.Tn ZFS
allows devices to be associated with pools as
.Qq hot spares .
These devices are not actively used in the pool, but when an active device
fails, it is automatically replaced by a hot spare. To create a pool with hot
spares, specify a
.Qq spare
.No vdev
with any number of devices. For example,
.Bd -literal -offset 2n
.Li # Ic zpool create pool mirror da0 da1 spare da2 da3
.Ed
.Pp
Spares can be shared across multiple pools, and can be added with the
.Qq Nm Cm add
command and removed with the
.Qq Nm Cm remove
command. Once a spare replacement is initiated, a new "spare"
.No vdev
is created
within the configuration that will remain there until the original device is
replaced. At this point, the hot spare becomes available again if another
device fails.
.Pp
If a pool has a shared spare that is currently being used, the pool can not be
exported since other pools may use this shared spare, which may lead to
potential data corruption.
.Pp
An in-progress spare replacement can be cancelled by detaching the hot spare.
If the original faulted device is detached, then the hot spare assumes its
place in the configuration, and is removed from the spare list of all active
pools.
.Pp
Spares cannot replace log devices.
.Pp
This feature requires a userland helper.
.Ss Intent Log
The
.Tn ZFS
Intent Log
.Pq Tn ZIL
satisfies
.Tn POSIX
requirements for synchronous transactions. For instance, databases often
require their transactions to be on stable storage devices when returning from
a system call.
.Tn NFS
and other applications can also use
.Xr fsync 2
to ensure data stability. By default, the intent log is allocated from blocks
within the main pool. However, it might be possible to get better performance
using separate intent log devices such as
.Tn NVRAM
or a dedicated disk. For example:
.Bd -literal -offset 2n
.Li # Ic zpool create pool da0 da1 log da2
.Ed
.Pp
Multiple log devices can also be specified, and they can be mirrored. See the
.Sx EXAMPLES
section for an example of mirroring multiple log devices.
.Pp
Log devices can be added, replaced, attached, detached, imported and exported
as part of the larger pool. Mirrored log devices can be removed by specifying
the top-level mirror for the log.
.Ss Cache devices
Devices can be added to a storage pool as "cache devices." These devices
provide an additional layer of caching between main memory and disk. For
read-heavy workloads, where the working set size is much larger than what can
be cached in main memory, using cache devices allow much more of this working
set to be served from low latency media. Using cache devices provides the
greatest performance improvement for random read-workloads of mostly static
content.
.Pp
To create a pool with cache devices, specify a "cache"
.No vdev
with any number of devices. For example:
.Bd -literal -offset 2n
.Li # Ic zpool create pool da0 da1 cache da2 da3
.Ed
.Pp
Cache devices cannot be mirrored or part of a
.No raidz
configuration. If a read
error is encountered on a cache device, that read
.Tn I/O
is reissued to the original storage pool device, which might be part of a
mirrored or
.No raidz
configuration.
.Pp
The content of the cache devices is considered volatile, as is the case with
other system caches.
.Ss Properties
Each pool has several properties associated with it. Some properties are
read-only statistics while others are configurable and change the behavior of
the pool. The following are read-only properties:
.Bl -tag -width "dedupratio"
.It Sy alloc
Amount of storage space within the pool that has been physically allocated.
.It Sy capacity
Percentage of pool space used. This property can also be referred to by its
shortened column name, "cap".
.It Sy comment
A text string consisting of printable ASCII characters that will be stored
such that it is available even if the pool becomes faulted.  An administrator
can provide additional information about a pool using this property.
.It Sy dedupratio
The deduplication ratio specified for a pool, expressed as a multiplier.
For example, a
.Sy dedupratio
value of 1.76 indicates that 1.76 units of data were stored but only 1 unit of disk space was actually consumed. See
.Xr zfs 8
for a description of the deduplication feature.
.It Sy expandsize
Amount of uninitialized space within the pool or device that can be used to
increase the total capacity of the pool.
Uninitialized space consists of
any space on an EFI labeled vdev which has not been brought online
.Pq i.e. zpool online -e .
This space occurs when a LUN is dynamically expanded.
.It Sy fragmentation
The amount of fragmentation in the pool.
.It Sy free
Number of blocks within the pool that are not allocated.
.It Sy freeing
After a file system or snapshot is destroyed, the space it was using is
returned to the pool asynchronously.
.Sy freeing
is the amount of space remaining to be reclaimed.
Over time
.Sy freeing
will decrease while
.Sy free
increases.
.It Sy guid
A unique identifier for the pool.
.It Sy health
The current health of the pool. Health can be
.Qq Sy ONLINE ,
.Qq Sy DEGRADED ,
.Qq Sy FAULTED ,
.Qq Sy OFFLINE ,
.Qq Sy REMOVED ,
or
.Qq Sy UNAVAIL .
.It Sy size
Total size of the storage pool.
.It Sy unsupported@ Ns Ar feature_guid
Information about unsupported features that are enabled on the pool.
See
.Xr zpool-features 7
for details.
.It Sy used
Amount of storage space used within the pool.
.El
.Pp
The space usage properties report actual physical space available to the
storage pool. The physical space can be different from the total amount of
space that any contained datasets can actually use. The amount of space used in
a
.No raidz
configuration depends on the characteristics of the data being written.
In addition,
.Tn ZFS
reserves some space for internal accounting that the
.Xr zfs 8
command takes into account, but the
.Xr zpool 8
command does not. For non-full pools of a reasonable size, these effects should
be invisible. For small pools, or pools that are close to being completely
full, these discrepancies may become more noticeable.
.Pp
The following property can be set at creation time and import time:
.Bl -tag -width 2n
.It Sy altroot
Alternate root directory. If set, this directory is prepended to any mount
points within the pool. This can be used when examining an unknown pool where
the mount points cannot be trusted, or in an alternate boot environment, where
the typical paths are not valid.
.Sy altroot
is not a persistent property. It is valid only while the system is up.
Setting
.Sy altroot
defaults to using
.Cm cachefile=none ,
though this may be overridden using an explicit setting.
.El
.Pp
The following property can only be set at import time:
.Bl -tag -width 2n
.It Sy readonly Ns = Ns Cm on No | Cm off
If set to
.Cm on ,
pool will be imported in read-only mode with the following restrictions:
.Bl -bullet -offset 2n
.It
Synchronous data in the intent log will not be accessible
.It
Properties of the pool can not be changed
.It
Datasets of this pool can only be mounted read-only
.It
To write to a read-only pool, a export and import of the pool is required.
.El
.Pp
This property can also be referred to by its shortened column name,
.Sy rdonly .
.El
.Pp
The following properties can be set at creation time and import time, and later
changed with the
.Ic zpool set
command:
.Bl -tag -width 2n
.It Sy autoexpand Ns = Ns Cm on No | Cm off
Controls automatic pool expansion when the underlying LUN is grown. If set to
.Qq Cm on ,
the pool will be resized according to the size of the expanded
device. If the device is part of a mirror or
.No raidz
then all devices within that
.No mirror/ Ns No raidz
group must be expanded before the new space is made available to
the pool. The default behavior is
.Qq off .
This property can also be referred to by its shortened column name,
.Sy expand .
.It Sy autoreplace Ns = Ns Cm on No | Cm off
Controls automatic device replacement. If set to
.Qq Cm off ,
device replacement must be initiated by the administrator by using the
.Qq Nm Cm replace
command. If set to
.Qq Cm on ,
any new device, found in the same
physical location as a device that previously belonged to the pool, is
automatically formatted and replaced. The default behavior is
.Qq Cm off .
This property can also be referred to by its shortened column name, "replace".
.It Sy bootfs Ns = Ns Ar pool Ns / Ns Ar dataset
Identifies the default bootable dataset for the root pool. This property is
expected to be set mainly by the installation and upgrade programs.
.It Sy cachefile Ns = Ns Ar path No | Cm none
Controls the location of where the pool configuration is cached. Discovering
all pools on system startup requires a cached copy of the configuration data
that is stored on the root file system. All pools in this cache are
automatically imported when the system boots. Some environments, such as
install and clustering, need to cache this information in a different location
so that pools are not automatically imported. Setting this property caches the
pool configuration in a different location that can later be imported with
.Qq Nm Cm import Fl c .
Setting it to the special value
.Qq Cm none
creates a temporary pool that is never cached, and the special value
.Cm ''
(empty string) uses the default location.
.It Sy comment Ns = Ns Ar text
A text string consisting of printable ASCII characters that will be stored
such that it is available even if the pool becomes faulted.
An administrator can provide additional information about a pool using this
property.
.It Sy dedupditto Ns = Ns Ar number
Threshold for the number of block ditto copies. If the reference count for a
deduplicated block increases above this number, a new ditto copy of this block
is automatically stored. Default setting is
.Cm 0
which causes no ditto copies to be created for deduplicated blocks.
The miniumum legal nonzero setting is 100.
.It Sy delegation Ns = Ns Cm on No | Cm off
Controls whether a non-privileged user is granted access based on the dataset
permissions defined on the dataset. See
.Xr zfs 8
for more information on
.Tn ZFS
delegated administration.
.It Sy failmode Ns = Ns Cm wait No | Cm continue No | Cm panic
Controls the system behavior in the event of catastrophic pool failure. This
condition is typically a result of a loss of connectivity to the underlying
storage device(s) or a failure of all devices within the pool. The behavior of
such an event is determined as follows:
.Bl -tag -width indent
.It Sy wait
Blocks all
.Tn I/O
access until the device connectivity is recovered and the errors are cleared.
This is the default behavior.
.It Sy continue
Returns
.Em EIO
to any new write
.Tn I/O
requests but allows reads to any of the remaining healthy devices. Any write
requests that have yet to be committed to disk would be blocked.
.It Sy panic
Prints out a message to the console and generates a system crash dump.
.El
.It Sy feature@ Ns Ar feature_name Ns = Ns Sy enabled
The value of this property is the current state of
.Ar feature_name .
The only valid value when setting this property is
.Sy enabled
which moves
.Ar feature_name
to the enabled state.
See
.Xr zpool-features 7
for details on feature states.
.It Sy listsnaps Ns = Ns Cm on No | Cm off
Controls whether information about snapshots associated with this pool is
output when
.Qq Nm zfs Cm list
is run without the
.Fl t
option. The default value is
.Cm off .
.It Sy version Ns = Ns Ar version
The current on-disk version of the pool. This can be increased, but never
decreased. The preferred method of updating pools is with the
.Qq Nm Cm upgrade
command, though this property can be used when a specific version is needed
for backwards compatibility.
Once feature flags is enabled on a pool this property will no longer have a
value.
.El
.Sh SUBCOMMANDS
All subcommands that modify state are logged persistently to the pool in their
original form.
.Pp
The
.Nm
command provides subcommands to create and destroy storage pools, add capacity
to storage pools, and provide information about the storage pools. The following
subcommands are supported:
.Bl -tag -width 2n
.It Xo
.Nm
.Op Fl \&?
.Xc
.Pp
Displays a help message.
.It Xo
.Nm
.Cm add
.Op Fl fn
.Ar pool vdev ...
.Xc
.Pp
Adds the specified virtual devices to the given pool. The
.No vdev
specification is described in the
.Qq Sx Virtual Devices
section. The behavior of the
.Fl f
option, and the device checks performed are described in the
.Qq Nm Cm create
subcommand.
.Bl -tag -width indent
.It Fl f
Forces use of
.Ar vdev ,
even if they appear in use or specify a conflicting replication level.
Not all devices can be overridden in this manner.
.It Fl n
Displays the configuration that would be used without actually adding the
.Ar vdev Ns s.
The actual pool creation can still fail due to insufficient privileges or device
sharing.
.Pp
Do not add a disk that is currently configured as a quorum device to a zpool.
After a disk is in the pool, that disk can then be configured as a quorum
device.
.El
.It Xo
.Nm
.Cm attach
.Op Fl f
.Ar pool device new_device
.Xc
.Pp
Attaches
.Ar new_device
to an existing
.Sy zpool
device. The existing device cannot be part of a
.No raidz
configuration. If
.Ar device
is not currently part of a mirrored configuration,
.Ar device
automatically transforms into a two-way mirror of
.Ar device No and Ar new_device .
If
.Ar device
is part of a two-way mirror, attaching
.Ar new_device
creates a three-way mirror, and so on. In either case,
.Ar new_device
begins to resilver immediately.
.Bl -tag -width indent
.It Fl f
Forces use of
.Ar new_device ,
even if its appears to be in use. Not all devices can be overridden in this
manner.
.El
.It Xo
.Nm
.Cm clear
.Op Fl F Op Fl n
.Ar pool
.Op Ar device
.Xc
.Pp
Clears device errors in a pool. If no arguments are specified, all device
errors within the pool are cleared. If one or more devices is specified, only
those errors associated with the specified device or devices are cleared.
.Bl -tag -width indent
.It Fl F
Initiates recovery mode for an unopenable pool. Attempts to discard the last
few transactions in the pool to return it to an openable state. Not all damaged
pools can be recovered by using this option. If successful, the data from the
discarded transactions is irretrievably lost.
.It Fl n
Used in combination with the
.Fl F
flag. Check whether discarding transactions would make the pool openable, but
do not actually discard any transactions.
.El
.It Xo
.Nm
.Cm create
.Op Fl fnd
.Op Fl o Ar property Ns = Ns Ar value
.Ar ...
.Op Fl O Ar file-system-property Ns = Ns Ar value
.Ar ...
.Op Fl m Ar mountpoint
.Op Fl R Ar root
.Ar pool vdev ...
.Xc
.Pp
Creates a new storage pool containing the virtual devices specified on the
command line. The pool name must begin with a letter, and can only contain
alphanumeric characters as well as underscore ("_"), dash ("-"), and period
("."). The pool names "mirror", "raidz", "spare" and "log" are reserved, as are
names beginning with the pattern "c[0-9]". The
.No vdev
specification is described in the
.Qq Sx Virtual Devices
section.
.Pp
The command verifies that each device specified is accessible and not currently
in use by another subsystem. There are some uses, such as being currently
mounted, or specified as the dedicated dump device, that prevents a device from
ever being used by
.Tn ZFS
Other uses, such as having a preexisting
.Sy UFS
file system, can be overridden with the
.Fl f
option.
.Pp
The command also checks that the replication strategy for the pool is
consistent. An attempt to combine redundant and non-redundant storage in a
single pool, or to mix disks and files, results in an error unless
.Fl f
is specified. The use of differently sized devices within a single
.No raidz
or mirror group is also flagged as an error unless
.Fl f
is specified.
.Pp
Unless the
.Fl R
option is specified, the default mount point is
.Qq Pa /pool .
The mount point must not exist or must be empty, or else the
root dataset cannot be mounted. This can be overridden with the
.Fl m
option.
.Pp
By default all supported features are enabled on the new pool unless the
.Fl d
option is specified.
.Bl -tag -width indent
.It Fl f
Forces use of
.Ar vdev Ns s,
even if they appear in use or specify a conflicting replication level.
Not all devices can be overridden in this manner.
.It Fl n
Displays the configuration that would be used without actually creating the
pool. The actual pool creation can still fail due to insufficient privileges or
device sharing.
.It Fl d
Do not enable any features on the new pool.
Individual features can be enabled by setting their corresponding properties
to
.Sy enabled
with the
.Fl o
option.
See
.Xr zpool-features 7
for details about feature properties.
.It Xo
.Fl o Ar property Ns = Ns Ar value
.Op Fl o Ar property Ns = Ns Ar value
.Ar ...
.Xc
Sets the given pool properties. See the
.Qq Sx Properties
section for a list of valid properties that can be set.
.It Xo
.Fl O
.Ar file-system-property Ns = Ns Ar value
.Op Fl O Ar file-system-property Ns = Ns Ar value
.Ar ...
.Xc
Sets the given file system properties in the root file system of the pool. See
.Xr zfs 8 Properties
for a list of valid properties that
can be set.
.It Fl R Ar root
Equivalent to
.Qq Fl o Cm cachefile=none,altroot= Ns Pa root
.It Fl m Ar mountpoint
Sets the mount point for the root dataset. The default mount point is
.Qq Pa /pool
or
.Qq Cm altroot Ns Pa /pool
if
.Sy altroot
is specified. The mount point must be an absolute path,
.Qq Cm legacy ,
or
.Qq Cm none .
For more information on dataset mount points, see
.Xr zfs 8 .
.El
.It Xo
.Nm
.Cm destroy
.Op Fl f
.Ar pool
.Xc
.Pp
Destroys the given pool, freeing up any devices for other use. This command
tries to unmount any active datasets before destroying the pool.
.Bl -tag -width indent
.It Fl f
Forces any active datasets contained within the pool to be unmounted.
.El
.It Xo
.Nm
.Cm detach
.Ar pool device
.Xc
.Pp
Detaches
.Ar device
from a mirror. The operation is refused if there are no other valid replicas
of the data.
.It Xo
.Nm
.Cm export
.Op Fl f
.Ar pool ...
.Xc
.Pp
Exports the given pools from the system. All devices are marked as exported,
but are still considered in use by other subsystems. The devices can be moved
between systems (even those of different endianness) and imported as long as a
sufficient number of devices are present.
.Pp
Before exporting the pool, all datasets within the pool are unmounted. A pool
can not be exported if it has a shared spare that is currently being used.
.Pp
For pools to be portable, you must give the
.Nm
command whole disks, not just slices, so that
.Tn ZFS
can label the disks with portable
.Sy EFI
labels. Otherwise, disk drivers on platforms of different endianness will not
recognize the disks.
.Bl -tag -width indent
.It Fl f
Forcefully unmount all datasets, using the
.Qq Nm unmount Fl f
command.
.Pp
This command will forcefully export the pool even if it has a shared spare that
is currently being used. This may lead to potential data corruption.
.El
.It Xo
.Nm
.Cm get
.Op Fl Hp
.Op Fl o Ar field Ns Op , Ns Ar ...
.Ar all | property Ns Op , Ns Ar ...
.Ar pool ...
.Xc
.Pp
Retrieves the given list of properties (or all properties if
.Qq Cm all
is used) for the specified storage pool(s). These properties are displayed with
the following fields:
.Bl -column -offset indent "property"
.It name Ta Name of storage pool
.It property Ta Property name
.It value Ta Property value
.It source Ta Property source, either 'default' or 'local'.
.El
.Pp
See the
.Qq Sx Properties
section for more information on the available pool properties.
.It Fl H
Scripted mode. Do not display headers, and separate fields by a single tab
instead of arbitrary space.
.It Fl p
Display numbers in parsable (exact) values.
.It Fl o Ar field
A comma-separated list of columns to display.
.Sy name Ns , Ns
.Sy property Ns , Ns
.Sy value Ns , Ns
.Sy source
is the default value.
.It Xo
.Nm
.Cm history
.Op Fl il
.Op Ar pool
.Ar ...
.Xc
.Pp
Displays the command history of the specified pools or all pools if no pool is
specified.
.Bl -tag -width indent
.It Fl i
Displays internally logged
.Tn ZFS
events in addition to user initiated events.
.It Fl l
Displays log records in long format, which in addition to standard format
includes, the user name, the hostname, and the zone in which the operation was
performed.
.El
.It Xo
.Nm
.Cm import
.Op Fl d Ar dir | Fl c Ar cachefile
.Op Fl D
.Xc
.Pp
Lists pools available to import. If the
.Fl d
option is not specified, this command searches for devices in
.Qq Pa /dev .
The
.Fl d
option can be specified multiple times, and all directories are searched. If
the device appears to be part of an exported pool, this command displays a
summary of the pool with the name of the pool, a numeric identifier, as well as
the
.No vdev
layout and current health of the device for each device or file.
Destroyed pools, pools that were previously destroyed with the
.Qq Nm Cm destroy
command, are not listed unless the
.Fl D
option is specified.
.Pp
The numeric identifier is unique, and can be used instead of the pool name when
multiple exported pools of the same name are available.
.Bl -tag -width indent
.It Fl c Ar cachefile
Reads configuration from the given
.Ar cachefile
that was created with the
.Qq Sy cachefile
pool property. This
.Ar cachefile
is used instead of searching for devices.
.It Fl d Ar dir
Searches for devices or files in
.Ar dir .
The
.Fl d
option can be specified multiple times.
.It Fl D
Lists destroyed pools only.
.El
.It Xo
.Nm
.Cm import
.Op Fl o Ar mntopts
.Op Fl o Ar property Ns = Ns Ar value
.Ar ...
.Op Fl d Ar dir | Fl c Ar cachefile
.Op Fl D
.Op Fl f
.Op Fl m
.Op Fl N
.Op Fl R Ar root
.Op Fl F Op Fl n
.Fl a
.Xc
.Pp
Imports all pools found in the search directories. Identical to the previous
command, except that all pools with a sufficient number of devices available
are imported. Destroyed pools, pools that were previously destroyed with the
.Qq Nm Cm destroy
command, will not be imported unless the
.Fl D
option is specified.
.Bl -tag -width indent
.It Fl o Ar mntopts
Comma-separated list of mount options to use when mounting datasets within the
pool. See
.Xr zfs 8
for a description of dataset properties and mount options.
.It Fl o Ar property Ns = Ns Ar value
Sets the specified property on the imported pool. See the
.Qq Sx Properties
section for more information on the available pool properties.
.It Fl c Ar cachefile
Reads configuration from the given
.Ar cachefile
that was created with the
.Qq Sy cachefile
pool property. This
.Ar cachefile
is used instead of searching for devices.
.It Fl d Ar dir
Searches for devices or files in
.Ar dir .
The
.Fl d
option can be specified multiple times. This option is incompatible with the
.Fl c
option.
.It Fl D
Imports destroyed pools only. The
.Fl f
option is also required.
.It Fl f
Forces import, even if the pool appears to be potentially active.
.It Fl m
Allows a pool to import when there is a missing log device. Recent transactions
can be lost because the log device will be discarded.
.It Fl N
Import the pool without mounting any file systems.
.It Fl R Ar root
Sets the
.Qq Sy cachefile
property to
.Qq Cm none
and the
.Qq Sy altroot
property to
.Qq Ar root
.It Fl F
Recovery mode for a non-importable pool. Attempt to return the pool to an
importable state by discarding the last few transactions. Not all damaged pools
can be recovered by using this option. If successful, the data from the
discarded transactions is irretrievably lost. This option is ignored if the
pool is importable or already imported.
.It Fl n
Used with the
.Fl F
recovery option. Determines whether a non-importable pool can be made
importable again, but does not actually perform the pool recovery. For more
details about pool recovery mode, see the
.Fl F
option, above.
.It Fl a
Searches for and imports all pools found.
.El
.It Xo
.Nm
.Cm import
.Op Fl o Ar mntopts
.Op Fl o Ar property Ns = Ns Ar value
.Ar ...
.Op Fl d Ar dir | Fl c Ar cachefile
.Op Fl D
.Op Fl f
.Op Fl m
.Op Fl N
.Op Fl R Ar root
.Op Fl F Op Fl n
.Ar pool | id
.Op Ar newpool
.Xc
.Pp
Imports a specific pool. A pool can be identified by its name or the numeric
identifier. If
.Ar newpool
is specified, the pool is imported using the name
.Ar newpool .
Otherwise, it is imported with the same name as its exported name.
.Pp
If a device is removed from a system without running
.Qq Nm Cm export
first, the device appears as potentially active. It cannot be determined if
this was a failed export, or whether the device is really in use from another
host. To import a pool in this state, the
.Fl f
option is required.
.Bl -tag -width indent
.It Fl o Ar mntopts
Comma-separated list of mount options to use when mounting datasets within the
pool. See
.Xr zfs 8
for a description of dataset properties and mount options.
.It Fl o Ar property Ns = Ns Ar value
Sets the specified property on the imported pool. See the
.Qq Sx Properties
section for more information on the available pool properties.
.It Fl c Ar cachefile
Reads configuration from the given
.Ar cachefile
that was created with the
.Qq Sy cachefile
pool property. This
.Ar cachefile
is used instead of searching for devices.
.It Fl d Ar dir
Searches for devices or files in
.Ar dir .
The
.Fl d
option can be specified multiple times. This option is incompatible with the
.Fl c
option.
.It Fl D
Imports destroyed pools only. The
.Fl f
option is also required.
.It Fl f
Forces import, even if the pool appears to be potentially active.
.It Fl m
Allows a pool to import when there is a missing log device. Recent transactions
can be lost because the log device will be discarded.
.It Fl N
Import the pool without mounting any file systems.
.It Fl R Ar root
Equivalent to
.Qq Fl o Cm cachefile=none,altroot= Ns Pa root
.It Fl F
Recovery mode for a non-importable pool. Attempt to return the pool to an
importable state by discarding the last few transactions. Not all damaged pools
can be recovered by using this option. If successful, the data from the
discarded transactions is irretrievably lost. This option is ignored if the
pool is importable or already imported.
.It Fl n
Used with the
.Fl F
recovery option. Determines whether a non-importable pool can be made
importable again, but does not actually perform the pool recovery. For more
details about pool recovery mode, see the
.Fl F
option, above.
.El
.It Xo
.Nm
.Cm iostat
.Op Fl T Cm d Ns | Ns Cm u
.Op Fl v
.Op Ar pool
.Ar ...
.Op Ar interval Op Ar count
.Xc
.Pp
Displays
.Tn I/O
statistics for the given pools. When given an interval, the statistics are
printed every
.Ar interval
seconds until
.Sy Ctrl-C
is pressed. If no
.Ar pools
are specified, statistics for every pool in the system is shown. If
.Ar count
is specified, the command exits after
.Ar count
reports are printed.
.Bl -tag -width indent
.It Fl T Cm d Ns | Ns Cm u
Print a timestamp.
.Pp
Use modifier
.Cm d
for standard date format. See
.Xr date 1 .
Use modifier
.Cm u
for unixtime
.Pq equals Qq Ic date +%s .
.It Fl v
Verbose statistics. Reports usage statistics for individual
.No vdev Ns s
within the pool, in addition to the pool-wide statistics.
.El
.It Xo
.Nm
.Cm labelclear
.Op Fl f
.Ar device
.Xc
.Pp
Removes
.Tn ZFS
label information from the specified
.Ar device .
The
.Ar device
must not be part of an active pool configuration.
.Bl -tag -width indent
.It Fl f
Treat exported or foreign devices as inactive.
.El
.It Xo
.Nm
.Cm list
.Op Fl Hpv
.Op Fl o Ar property Ns Op , Ns Ar ...
.Op Fl T Cm d Ns | Ns Cm u
.Op Ar pool
.Ar ...
.Op Ar inverval Op Ar count
.Xc
.Pp
Lists the given pools along with a health status and space usage. If no
.Ar pools
are specified, all pools in the system are listed.
.Pp
When given an interval, the output is printed every
.Ar interval
seconds until
.Sy Ctrl-C
is pressed. If
.Ar count
is specified, the command exits after
.Ar count
reports are printed.
.Bl -tag -width indent
.It Fl T Cm d Ns | Ns Cm u
Print a timestamp.
.Pp
Use modifier
.Cm d
for standard date format. See
.Xr date 1 .
Use modifier
.Cm u
for unixtime
.Pq equals Qq Ic date +%s .
.It Fl H
Scripted mode. Do not display headers, and separate fields by a single tab
instead of arbitrary space.
.It Fl p
Display numbers in parsable (exact) values.
.It Fl v
Verbose statistics. Reports usage statistics for individual
.Em vdevs
within
the pool, in addition to the pool-wide statistics.
.It Fl o Ar property Ns Op , Ns Ar ...
Comma-separated list of properties to display. See the
.Qq Sx Properties
section for a list of valid properties. The default list is
.Sy name ,
.Sy size ,
.Sy used ,
.Sy available ,
.Sy fragmentation ,
.Sy expandsize ,
.Sy capacity  ,
.Sy health ,
.Sy altroot .
.It Fl T Cm d Ns | Ns Cm u
Print a timestamp.
.Pp
Use modifier
.Cm d
for standard date format. See
.Xr date 1 .
Use modifier
.Cm u
for unixtime
.Pq equals Qq Ic date +%s .
.El
.It Xo
.Nm
.Cm offline
.Op Fl t
.Ar pool device ...
.Xc
.Pp
Takes the specified physical device offline. While the
.Ar device
is offline, no attempt is made to read or write to the device.
.Bl -tag -width indent
.It Fl t
Temporary. Upon reboot, the specified physical device reverts to its previous
state.
.El
.It Xo
.Nm
.Cm online
.Op Fl e
.Ar pool device ...
.Xc
.Pp
Brings the specified physical device online.
.Pp
This command is not applicable to spares or cache devices.
.Bl -tag -width indent
.It Fl e
Expand the device to use all available space. If the device is part of a mirror
or
.No raidz
then all devices must be expanded before the new space will become
available to the pool.
.El
.It Xo
.Nm
.Cm reguid
.Ar pool
.Xc
.Pp
Generates a new unique identifier for the pool.  You must ensure that all
devices in this pool are online and healthy before performing this action.
.It Xo
.Nm
.Cm remove
.Ar pool device ...
.Xc
.Pp
Removes the specified device from the pool. This command currently only
supports removing hot spares, cache, and log devices. A mirrored log device can
be removed by specifying the top-level mirror for the log. Non-log devices that
are part of a mirrored configuration can be removed using the
.Qq Nm Cm detach
command. Non-redundant and
.No raidz
devices cannot be removed from a pool.
.It Xo
.Nm
.Cm reopen
.Ar pool
.Xc
.Pp
Reopen all the vdevs associated with the pool.
.It Xo
.Nm
.Cm replace
.Op Fl f
.Ar pool device
.Op Ar new_device
.Xc
.Pp
Replaces
.Ar old_device
with
.Ar new_device .
This is equivalent to attaching
.Ar new_device ,
waiting for it to resilver, and then detaching
.Ar old_device .
.Pp
The size of
.Ar new_device
must be greater than or equal to the minimum size
of all the devices in a mirror or
.No raidz
configuration.
.Pp
.Ar new_device
is required if the pool is not redundant. If
.Ar new_device
is not specified, it defaults to
.Ar old_device .
This form of replacement is useful after an existing disk has failed and has
been physically replaced. In this case, the new disk may have the same
.Pa /dev
path as the old device, even though it is actually a different disk.
.Tn ZFS
recognizes this.
.Bl -tag -width indent
.It Fl f
Forces use of
.Ar new_device ,
even if its appears to be in use. Not all devices can be overridden in this
manner.
.El
.It Xo
.Nm
.Cm scrub
.Op Fl s
.Ar pool ...
.Xc
.Pp
Begins a scrub. The scrub examines all data in the specified pools to verify
that it checksums correctly. For replicated (mirror or
.No raidz )
devices,
.Tn ZFS
automatically repairs any damage discovered during the scrub. The
.Qq Nm 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
.Tn ZFS
knows to be out of date (for example, when attaching a new device to a mirror
or replacing an existing device), whereas scrubbing examines all data to
discover silent errors due to hardware faults or disk failure.
.Pp
Because scrubbing and resilvering are
.Tn I/O Ns -intensive
operations,
.Tn ZFS
only allows one at a time. If a scrub is already in progress, the
.Qq Nm Cm scrub
command returns an error. To start a new scrub, you have to stop the old scrub
with the
.Qq Nm Cm scrub Fl s
command first. If a resilver is in progress,
.Tn ZFS
does not allow a scrub to be started until the resilver completes.
.Bl -tag -width indent
.It Fl s
Stop scrubbing.
.El
.It Xo
.Nm
.Cm set
.Ar property Ns = Ns Ar value pool
.Xc
.Pp
Sets the given property on the specified pool. See the
.Qq Sx Properties
section for more information on what properties can be set and acceptable
values.
.It Xo
.Nm
.Cm split
.Op Fl n
.Op Fl R Ar altroot
.Op Fl o Ar mntopts
.Op Fl o Ar property Ns = Ns Ar value
.Ar pool newpool
.Op Ar device ...
.Xc
.Pp
Splits off one disk from each mirrored top-level
.No vdev
in a pool and creates a new pool from the split-off disks. The original pool
must be made up of one or more mirrors and must not be in the process of
resilvering. The
.Cm split
subcommand chooses the last device in each mirror
.No vdev
unless overridden by a device specification on the command line.
.Pp
When using a
.Ar device
argument,
.Cm split
includes the specified device(s) in a new pool and, should any devices remain
unspecified, assigns the last device in each mirror
.No vdev
to that pool, as it does normally. If you are uncertain about the outcome of a
.Cm split
command, use the
.Fl n
("dry-run") option to ensure your command will have the effect you intend.
.Bl -tag -width indent
.It Fl R Ar altroot
Automatically import the newly created pool after splitting, using the
specified
.Ar altroot
parameter for the new pool's alternate root. See the
.Sy altroot
description in the
.Qq Sx Properties
section, above.
.It Fl n
Displays the configuration that would be created without actually splitting the
pool. The actual pool split could still fail due to insufficient privileges or
device status.
.It Fl o Ar mntopts
Comma-separated list of mount options to use when mounting datasets within the
pool. See
.Xr zfs 8
for a description of dataset properties and mount options. Valid only in
conjunction with the
.Fl R
option.
.It Fl o Ar property Ns = Ns Ar value
Sets the specified property on the new pool. See the
.Qq Sx Properties
section, above, for more information on the available pool properties.
.El
.It Xo
.Nm
.Cm status
.Op Fl vx
.Op Fl T Cm d Ns | Ns Cm u
.Op Ar pool
.Ar ...
.Op Ar interval Op Ar count
.Xc
.Pp
Displays the detailed health status for the given pools. If no
.Ar pool
is specified, then the status of each pool in the system is displayed. For more
information on pool and device health, see the
.Qq Sx Device Failure and Recovery
section.
.Pp
When given an interval, the output is printed every
.Ar interval
seconds until
.Sy Ctrl-C
is pressed. If
.Ar count
is specified, the command exits after
.Ar count
reports are printed.
.Pp
If a scrub or resilver is in progress, this command reports the percentage
done and the estimated time to completion. Both of these are only approximate,
because the amount of data in the pool and the other workloads on the system
can change.
.Bl -tag -width indent
.It Fl x
Only display status for pools that are exhibiting errors or are otherwise
unavailable.
Warnings about pools not using the latest on-disk format, having non-native
block size or disabled features will not be included.
.It Fl v
Displays verbose data error information, printing out a complete list of all
data errors since the last complete pool scrub.
.It Fl T Cm d Ns | Ns Cm u
Print a timestamp.
.Pp
Use modifier
.Cm d
for standard date format. See
.Xr date 1 .
Use modifier
.Cm u
for unixtime
.Pq equals Qq Ic date +%s .
.El
.It Xo
.Nm
.Cm upgrade
.Op Fl v
.Xc
.Pp
Displays pools which do not have all supported features enabled and pools
formatted using a legacy
.Tn ZFS
version number.
These pools can continue to be used, but some features may not be available.
Use
.Nm Cm upgrade Fl a
to enable all features on all pools.
.Bl -tag -width indent
.It Fl v
Displays legacy
.Tn ZFS
versions supported by the current software.
See
.Xr zpool-features 7
for a description of feature flags features supported by the current software.
.El
.It Xo
.Nm
.Cm upgrade
.Op Fl V Ar version
.Fl a | Ar pool ...
.Xc
.Pp
Enables all supported features on the given pool.
Once this is done, the pool will no longer be accessible on systems that do
not support feature flags.
See
.Xr zpool-features 7
for details on compatibility with systems that support feature flags, but do
not support all features enabled on the pool.
.Bl -tag -width indent
.It Fl a
Enables all supported features on all pools.
.It Fl V Ar version
Upgrade to the specified legacy version. If the
.Fl V
flag is specified, no features will be enabled on the pool.
This option can only be used to increase version number up to the last
supported legacy version number.
.El
.El
.Sh EXIT STATUS
The following exit values are returned:
.Bl -tag -offset 2n -width 2n
.It 0
Successful completion.
.It 1
An error occurred.
.It 2
Invalid command line options were specified.
.El
.Sh EXAMPLES
.Bl -tag -width 0n
.It Sy Example 1 No Creating a RAID-Z Storage Pool
.Pp
The following command creates a pool with a single
.No raidz
root
.No vdev
that consists of six disks.
.Bd -literal -offset 2n
.Li # Ic zpool create tank raidz da0 da1 da2 da3 da4 da5
.Ed
.It Sy Example 2 No Creating a Mirrored Storage Pool
.Pp
The following command creates a pool with two mirrors, where each mirror
contains two disks.
.Bd -literal -offset 2n
.Li # Ic zpool create tank mirror da0 da1 mirror da2 da3
.Ed
.It Sy Example 3 No Creating a Tn ZFS No Storage Pool by Using Partitions
.Pp
The following command creates an unmirrored pool using two GPT partitions.
.Bd -literal -offset 2n
.Li # Ic zpool create tank da0p3 da1p3
.Ed
.It Sy Example 4 No Creating a Tn ZFS No Storage Pool by Using Files
.Pp
The following command creates an unmirrored pool using files. While not
recommended, a pool based on files can be useful for experimental purposes.
.Bd -literal -offset 2n
.Li # Ic zpool create tank /path/to/file/a /path/to/file/b
.Ed
.It Sy Example 5 No Adding a Mirror to a Tn ZFS No Storage Pool
.Pp
The following command adds two mirrored disks to the pool
.Em tank ,
assuming the pool is already made up of two-way mirrors. The additional space
is immediately available to any datasets within the pool.
.Bd -literal -offset 2n
.Li # Ic zpool add tank mirror da2 da3
.Ed
.It Sy Example 6 No Listing Available Tn ZFS No Storage Pools
.Pp
The following command lists all available pools on the system.
.Bd -literal -offset 2n
.Li # Ic zpool list
NAME   SIZE  ALLOC   FREE   FRAG  EXPANDSZ    CAP  DEDUP  HEALTH  ALTROOT
pool  2.70T   473G  2.24T    33%         -    17%  1.00x  ONLINE  -
test  1.98G  89.5K  1.98G    48%         -     0%  1.00x  ONLINE  -
.Ed
.It Sy Example 7 No Listing All Properties for a Pool
.Pp
The following command lists all the properties for a pool.
.Bd -literal -offset 2n
.Li # Ic zpool get all pool
pool  size           2.70T       -
pool  capacity       17%         -
pool  altroot        -           default
pool  health         ONLINE      -
pool  guid           2501120270416322443  default
pool  version        28          default
pool  bootfs         pool/root   local
pool  delegation     on          default
pool  autoreplace    off         default
pool  cachefile      -           default
pool  failmode       wait        default
pool  listsnapshots  off         default
pool  autoexpand     off         default
pool  dedupditto     0           default
pool  dedupratio     1.00x       -
pool  free           2.24T       -
pool  allocated      473G        -
pool  readonly       off         -
.Ed
.It Sy Example 8 No Destroying a Tn ZFS No Storage Pool
.Pp
The following command destroys the pool
.Qq Em tank
and any datasets contained within.
.Bd -literal -offset 2n
.Li # Ic zpool destroy -f tank
.Ed
.It Sy Example 9 No Exporting a Tn ZFS No Storage Pool
.Pp
The following command exports the devices in pool
.Em tank
so that they can be relocated or later imported.
.Bd -literal -offset 2n
.Li # Ic zpool export tank
.Ed
.It Sy Example 10 No Importing a Tn ZFS No Storage Pool
.Pp
The following command displays available pools, and then imports the pool
.Qq Em tank
for use on the system.
.Pp
The results from this command are similar to the following:
.Bd -literal -offset 2n
.Li # Ic zpool import

  pool: tank
    id: 15451357997522795478
 state: ONLINE
action: The pool can be imported using its name or numeric identifier.
config:

        tank        ONLINE
          mirror    ONLINE
               da0  ONLINE
               da1  ONLINE
.Ed
.It Xo
.Sy Example 11
Upgrading All
.Tn ZFS
Storage Pools to the Current Version
.Xc
.Pp
The following command upgrades all
.Tn ZFS
Storage pools to the current version of
the software.
.Bd -literal -offset 2n
.Li # Ic zpool upgrade -a
This system is currently running ZFS pool version 28.
.Ed
.It Sy Example 12 No Managing Hot Spares
.Pp
The following command creates a new pool with an available hot spare:
.Bd -literal -offset 2n
.Li # Ic zpool create tank mirror da0 da1 spare da2
.Ed
.Pp
If one of the disks were to fail, the pool would be reduced to the degraded
state. The failed device can be replaced using the following command:
.Bd -literal -offset 2n
.Li # Ic zpool replace tank da0 da2
.Ed
.Pp
Once the data has been resilvered, the spare is automatically removed and is
made available should another device fails. The hot spare can be permanently
removed from the pool using the following command:
.Bd -literal -offset 2n
.Li # Ic zpool remove tank da2
.Ed
.It Xo
.Sy Example 13
Creating a
.Tn ZFS
Pool with Mirrored Separate Intent Logs
.Xc
.Pp
The following command creates a
.Tn ZFS
storage pool consisting of two, two-way
mirrors and mirrored log devices:
.Bd -literal -offset 2n
.Li # Ic zpool create pool mirror da0 da1 mirror da2 da3 log mirror da4 da5
.Ed
.It Sy Example 14 No Adding Cache Devices to a Tn ZFS No Pool
.Pp
The following command adds two disks for use as cache devices to a
.Tn ZFS
storage pool:
.Bd -literal -offset 2n
.Li # Ic zpool add pool cache da2 da3
.Ed
.Pp
Once added, the cache devices gradually fill with content from main memory.
Depending on the size of your cache devices, it could take over an hour for
them to fill. Capacity and reads can be monitored using the
.Cm iostat
subcommand as follows:
.Bd -literal -offset 2n
.Li # Ic zpool iostat -v pool 5
.Ed
.It Xo
.Sy Example 15
Displaying expanded space on a device
.Xc
.Pp
The following command dipslays the detailed information for the
.Em data
pool.
This pool is comprised of a single
.Em raidz
vdev where one of its
devices increased its capacity by 10GB.
In this example, the pool will not
be able to utilized this extra capacity until all the devices under the
.Em raidz
vdev have been expanded.
.Bd -literal -offset 2n
.Li # Ic zpool list -v data
NAME       SIZE  ALLOC   FREE   FRAG  EXPANDSZ    CAP  DEDUP  HEALTH  ALTROOT
data      23.9G  14.6G  9.30G    48%         -    61%  1.00x  ONLINE  -
  raidz1  23.9G  14.6G  9.30G    48%         -
    ada0      -      -      -      -         -
    ada1      -      -      -      -       10G
    ada2      -      -      -      -         -
.Ed
.It Xo
.Sy Example 16
Removing a Mirrored Log Device
.Xc
.Pp
The following command removes the mirrored log device
.Em mirror-2 .
.Pp
Given this configuration:
.Bd -literal -offset 2n
   pool: tank
  state: ONLINE
  scrub: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
                da0  ONLINE       0     0     0
                da1  ONLINE       0     0     0
           mirror-1  ONLINE       0     0     0
                da2  ONLINE       0     0     0
                da3  ONLINE       0     0     0
         logs
           mirror-2  ONLINE       0     0     0
                da4  ONLINE       0     0     0
                da5  ONLINE       0     0     0
.Ed
.Pp
The command to remove the mirrored log
.Em mirror-2
is:
.Bd -literal -offset 2n
.Li # Ic zpool remove tank mirror-2
.Ed
.It Xo
.Sy Example 17
Recovering a Faulted
.Tn ZFS
Pool
.Xc
.Pp
If a pool is faulted but recoverable, a message indicating this state is
provided by
.Qq Nm Cm status
if the pool was cached (see the
.Fl c Ar cachefile
argument above), or as part of the error output from a failed
.Qq Nm Cm import
of the pool.
.Pp
Recover a cached pool with the
.Qq Nm Cm clear
command:
.Bd -literal -offset 2n
.Li # Ic zpool clear -F data
Pool data returned to its state as of Tue Sep 08 13:23:35 2009.
Discarded approximately 29 seconds of transactions.
.Ed
.Pp
If the pool configuration was not cached, use
.Qq Nm Cm import
with the recovery mode flag:
.Bd -literal -offset 2n
.Li # Ic zpool import -F data
Pool data returned to its state as of Tue Sep 08 13:23:35 2009.
Discarded approximately 29 seconds of transactions.
.Ed
.El
.Sh SEE ALSO
.Xr zpool-features 7 ,
.Xr zfs 8 ,
.Xr zfsd 8
.Sh AUTHORS
This manual page is a
.Xr mdoc 7
reimplementation of the
.Tn OpenSolaris
manual page
.Em zpool(1M) ,
modified and customized for
.Fx
and licensed under the Common Development and Distribution License
.Pq Tn CDDL .
.Pp
The
.Xr mdoc 7
implementation of this manual page was initially written by
.An Martin Matuska Aq mm@FreeBSD.org .