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ZPOOL(8)			   BSD System Manager's Manual				 ZPOOL(8)

NAME
     zpool -- configures ZFS storage pools

SYNOPSIS
     zpool [-?]
     zpool add [-fn] pool vdev ...
     zpool attach [-f] pool device new_device
     zpool clear [-F [-n]] pool [device]
     zpool create [-fnd] [-o property=value] ... [-O file-system-property=value] ...
	   [-m mountpoint] [-R root] pool vdev ...
     zpool destroy [-f] pool
     zpool detach pool device
     zpool export [-f] pool ...
     zpool get [-Hp] [-o field[,...]] all | property[,...] pool ...
     zpool history [-il] [pool] ...
     zpool import [-d dir | -c cachefile] [-D]
     zpool import [-o mntopts] [-o property=value] ... [-d dir | -c cachefile] [-D] [-f] [-m]
	   [-N] [-R root] [-F [-n]] -a
     zpool import [-o mntopts] [-o property=value] ... [-d dir | -c cachefile] [-D] [-f] [-m]
	   [-N] [-R root] [-F [-n]] pool | id [newpool]
     zpool iostat [-T d|u] [-v] [pool] ...
     zpool labelclear [-f] device
     zpool list [-Hpv] [-o property[,...]] [-T d|u] [pool] ... [inverval [count]]
     zpool offline [-t] pool device ...
     zpool online [-e] pool device ...
     zpool reguid pool
     zpool remove pool device ...
     zpool reopen pool
     zpool replace [-f] pool device [new_device]
     zpool scrub [-s] pool ...
     zpool set property=value pool
     zpool split [-n] [-R altroot] [-o mntopts] [-o property=value] pool newpool [device ...]
     zpool status [-vx] [-T d|u] [pool] ... [interval [count]]
     zpool upgrade [-v]
     zpool upgrade [-V version] -a | pool ...

DESCRIPTION
     The zpool command configures ZFS storage pools. A storage pool is a collection of devices
     that provides physical storage and data replication for ZFS datasets.

     All datasets within a storage pool share the same space. See zfs(8) for information on man-
     aging datasets.

   Virtual Devices (vdevs)
     A "virtual device" (vdev) describes a single device or a collection of devices organized
     according to certain performance and fault characteristics. The following virtual devices
     are supported:

     disk    A block device, typically located under /dev.  ZFS can use individual slices or par-
	     titions, 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 geom(4) provider name. When given a
	     whole disk, ZFS automatically labels the disk, if necessary.

     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.

     mirror  A mirror of two or more devices. Data is replicated in an identical fashion across
	     all components of a mirror. A mirror with N disks of size X can hold X bytes and can
	     withstand (N-1) devices failing before data integrity is compromised.

     raidz   (or raidz1 raidz2 raidz3).  A variation on RAID-5 that allows for better distribu-
	     tion of parity and eliminates the "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 raidz group.

	     A raidz group can have single-, double- , or triple parity, meaning that the raidz
	     group can sustain one, two, or three failures, respectively, without losing any
	     data. The raidz1 vdev type specifies a single-parity raidz group; the raidz2 vdev
	     type specifies a double-parity raidz group; and the raidz3 vdev type specifies a
	     triple-parity raidz group. The raidz vdev type is an alias for raidz1.

	     A raidz group with N disks of size X with P parity disks can hold approximately
	     (N-P)*X bytes and can withstand P device(s) failing before data integrity is compro-
	     mised. The minimum number of devices in a raidz group is one more than the number of
	     parity disks. The recommended number is between 3 and 9 to help increase perfor-
	     mance.

     spare   A special pseudo-vdev which keeps track of available hot spares for a pool.  For
	     more information, see the "Hot Spares" section.

     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, raidz vdev
	     types are not supported for the intent log. For more information, see the "Intent
	     Log" section.

     cache   A device used to cache storage pool data. A cache device cannot be configured as a
	     mirror or raidz group. For more information, see the "Cache Devices" section.

     Virtual devices cannot be nested, so a mirror or raidz virtual device can only contain files
     or disks. Mirrors of mirrors (or other combinations) are not allowed.

     A pool can have any number of virtual devices at the top of the configuration (known as
     "root" vdevs). Data is dynamically distributed across all top-level devices to balance data
     among devices. As new virtual devices are added, ZFS automatically places data on the newly
     available devices.

     Virtual devices are specified one at a time on the command line, separated by whitespace.
     The keywords "mirror" and "raidz" are used to distinguish where a group ends and another
     begins. For example, the following creates two root vdevs, each a mirror of two disks:

       # zpool create mypool mirror da0 da1 mirror da2 da3

   Device Failure and Recovery
     ZFS supports a rich set of mechanisms for handling device failure and data corruption. All
     metadata and data is checksummed, and ZFS automatically repairs bad data from a good copy
     when corruption is detected.

     In order to take advantage of these features, a pool must make use of some form of redun-
     dancy, using either mirrored or raidz groups. While ZFS supports running in a non-redundant
     configuration, where each root 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.

     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 repli-
     cas to continue functioning.

     The health of the top-level vdev, such as mirror or raidz device, is potentially impacted by
     the state of its associated vdevs, or component devices. A top-level vdev or component
     device is in one of the following states:

     DEGRADED  One or more top-level vdevs is in the degraded state because one or more component
	       devices are offline. Sufficient replicas exist to continue functioning.

	       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:

		 o   The number of checksum errors exceeds acceptable levels and the device is
		     degraded as an indication that something may be wrong.  ZFS continues to use
		     the device as necessary.

		 o   The number of I/O errors exceeds acceptable levels. The device could not be
		     marked as faulted because there are insufficient replicas to continue func-
		     tioning.

     FAULTED   One or more top-level vdevs is in the faulted state because one or more component
	       devices are offline. Insufficient replicas exist to continue functioning.

	       One or more component devices is in the faulted state, and insufficient replicas
	       exist to continue functioning. The underlying conditions are as follows:

		 o   The device could be opened, but the contents did not match expected values.

		 o   The number of I/O errors exceeds acceptable levels and the device is faulted
		     to prevent further use of the device.

     OFFLINE   The device was explicitly taken offline by the "zpool offline" command.

     ONLINE    The device is online and functioning.

     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.

     UNAVAIL   The device could not be opened. If a pool is imported when a device was unavail-
	       able, then the device will be identified by a unique identifier instead of its
	       path since the path was never correct in the first place.

     If a device is removed and later reattached to the system, ZFS attempts to put the device
     online automatically. Device attach detection is hardware-dependent and might not be sup-
     ported on all platforms.

   Hot Spares
     ZFS allows devices to be associated with pools as "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 "spare" vdev with any number of
     devices. For example,

       # zpool create pool mirror da0 da1 spare da2 da3

     Spares can be shared across multiple pools, and can be added with the "zpool add" command
     and removed with the "zpool remove" command. Once a spare replacement is initiated, a new
     "spare" 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.

     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.

     An in-progress spare replacement can be cancelled by detaching the hot spare.  If the origi-
     nal 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.

     Spares cannot replace log devices.

   Intent Log
     The ZFS Intent Log (ZIL) satisfies POSIX requirements for synchronous transactions. For
     instance, databases often require their transactions to be on stable storage devices when
     returning from a system call.  NFS and other applications can also use 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 NVRAM or a dedicated disk. For example:

       # zpool create pool da0 da1 log da2

     Multiple log devices can also be specified, and they can be mirrored. See the EXAMPLES sec-
     tion for an example of mirroring multiple log devices.

     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.

   Cache devices
     Devices can be added to a storage pool as "cache devices." These devices provide an addi-
     tional 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.

     To create a pool with cache devices, specify a "cache" vdev with any number of devices. For
     example:

       # zpool create pool da0 da1 cache da2 da3

     Cache devices cannot be mirrored or part of a raidz configuration. If a read error is
     encountered on a cache device, that read I/O is reissued to the original storage pool
     device, which might be part of a mirrored or raidz configuration.

     The content of the cache devices is considered volatile, as is the case with other system
     caches.

   Properties
     Each pool has several properties associated with it. Some properties are read-only statis-
     tics while others are configurable and change the behavior of the pool. The following are
     read-only properties:

     alloc	 Amount of storage space within the pool that has been physically allocated.

     capacity	 Percentage of pool space used. This property can also be referred to by its
		 shortened column name, "cap".

     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.

     dedupratio  The deduplication ratio specified for a pool, expressed as a multiplier.  For
		 example, a 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 zfs(8) for a
		 description of the deduplication feature.

     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 (i.e. zpool
		 online -e).  This space occurs when a LUN is dynamically expanded.

     fragmentation
		 The amount of fragmentation in the pool.

     free	 Number of blocks within the pool that are not allocated.

     freeing	 After a file system or snapshot is destroyed, the space it was using is returned
		 to the pool asynchronously.  freeing is the amount of space remaining to be
		 reclaimed.  Over time freeing will decrease while free increases.

     guid	 A unique identifier for the pool.

     health	 The current health of the pool. Health can be "ONLINE", "DEGRADED", "FAULTED",
		 "OFFLINE", "REMOVED", or "UNAVAIL".

     size	 Total size of the storage pool.

     unsupported@feature_guid
		 Information about unsupported features that are enabled on the pool.  See
		 zpool-features(7) for details.

     used	 Amount of storage space used within the pool.

     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 raidz configuration depends on the charac-
     teristics of the data being written.  In addition, ZFS reserves some space for internal
     accounting that the zfs(8) command takes into account, but the 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.

     The following property can be set at creation time and import time:

     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.
	 altroot is not a persistent property. It is valid only while the system is up.  Setting
	 altroot defaults to using cachefile=none, though this may be overridden using an
	 explicit setting.

     The following property can only be set at import time:

     readonly=on | off
	 If set to on, pool will be imported in read-only mode with the following restrictions:

	   o   Synchronous data in the intent log will not be accessible

	   o   Properties of the pool can not be changed

	   o   Datasets of this pool can only be mounted read-only

	   o   To write to a read-only pool, a export and import of the pool is required.

	 This property can also be referred to by its shortened column name, rdonly.

     The following properties can be set at creation time and import time, and later changed with
     the zpool set command:

     autoexpand=on | off
	 Controls automatic pool expansion when the underlying LUN is grown. If set to "on", the
	 pool will be resized according to the size of the expanded device. If the device is part
	 of a mirror or raidz then all devices within that mirror/raidz group must be expanded
	 before the new space is made available to the pool. The default behavior is "off".  This
	 property can also be referred to by its shortened column name, expand.

     autoreplace=on | off
	 Controls automatic device replacement. If set to "off", device replacement must be ini-
	 tiated by the administrator by using the "zpool replace" command. If set to "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 "off".  This
	 property can also be referred to by its shortened column name, "replace".

     bootfs=pool/dataset
	 Identifies the default bootable dataset for the root pool. This property is expected to
	 be set mainly by the installation and upgrade programs.

     cachefile=path | 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 prop-
	 erty caches the pool configuration in a different location that can later be imported
	 with "zpool import -c".  Setting it to the special value "none" creates a temporary pool
	 that is never cached, and the special value '' (empty string) uses the default location.

     comment=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.

     dedupditto=number
	 Threshold for the number of block ditto copies. If the reference count for a dedupli-
	 cated block increases above this number, a new ditto copy of this block is automatically
	 stored. Default setting is 0 which causes no ditto copies to be created for deduplicated
	 blocks.  The miniumum legal nonzero setting is 100.

     delegation=on | off
	 Controls whether a non-privileged user is granted access based on the dataset permis-
	 sions defined on the dataset. See zfs(8) for more information on ZFS delegated adminis-
	 tration.

     failmode=wait | continue | 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:

	 wait	 Blocks all I/O access until the device connectivity is recovered and the errors
		 are cleared.  This is the default behavior.

	 continue
		 Returns EIO to any new write I/O requests but allows reads to any of the remain-
		 ing healthy devices. Any write requests that have yet to be committed to disk
		 would be blocked.

	 panic	 Prints out a message to the console and generates a system crash dump.

     feature@feature_name=enabled
	 The value of this property is the current state of feature_name.  The only valid value
	 when setting this property is enabled which moves feature_name to the enabled state.
	 See zpool-features(7) for details on feature states.

     listsnaps=on | off
	 Controls whether information about snapshots associated with this pool is output when
	 "zfs list" is run without the -t option. The default value is off.

     version=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 "zpool 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.

SUBCOMMANDS
     All subcommands that modify state are logged persistently to the pool in their original
     form.

     The zpool 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:

     zpool [-?]

	 Displays a help message.

     zpool add [-fn] pool vdev ...

	 Adds the specified virtual devices to the given pool. The vdev specification is
	 described in the "Virtual Devices" section. The behavior of the -f option, and the
	 device checks performed are described in the "zpool create" subcommand.

	 -f	 Forces use of vdev, even if they appear in use or specify a conflicting replica-
		 tion level.  Not all devices can be overridden in this manner.

	 -n	 Displays the configuration that would be used without actually adding the vdevs.
		 The actual pool creation can still fail due to insufficient privileges or device
		 sharing.

		 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.

     zpool attach [-f] pool device new_device

	 Attaches new_device to an existing zpool device. The existing device cannot be part of a
	 raidz configuration. If device is not currently part of a mirrored configuration, device
	 automatically transforms into a two-way mirror of device and new_device.  If device is
	 part of a two-way mirror, attaching new_device creates a three-way mirror, and so on. In
	 either case, new_device begins to resilver immediately.

	 -f	 Forces use of new_device, even if its appears to be in use. Not all devices can
		 be overridden in this manner.

     zpool clear [-F [-n]] pool [device]

	 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.

	 -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.

	 -n	 Used in combination with the -F flag. Check whether discarding transactions
		 would make the pool openable, but do not actually discard any transactions.

     zpool create [-fnd] [-o property=value] ... [-O file-system-property=value] ... [-m
	 mountpoint] [-R root] pool vdev ...

	 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 vdev specification is described in the "Virtual Devices" section.

	 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 ZFS Other
	 uses, such as having a preexisting UFS file system, can be overridden with the -f
	 option.

	 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 -f is specified. The use of differently sized
	 devices within a single raidz or mirror group is also flagged as an error unless -f is
	 specified.

	 Unless the -R option is specified, the default mount point is "/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 -m option.

	 By default all supported features are enabled on the new pool unless the -d option is
	 specified.

	 -f	 Forces use of vdevs, even if they appear in use or specify a conflicting repli-
		 cation level.	Not all devices can be overridden in this manner.

	 -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.

	 -d	 Do not enable any features on the new pool.  Individual features can be enabled
		 by setting their corresponding properties to enabled with the -o option.  See
		 zpool-features(7) for details about feature properties.

	 -o property=value [-o property=value] ...
		 Sets the given pool properties. See the "Properties" section for a list of valid
		 properties that can be set.

	 -O file-system-property=value [-O file-system-property=value] ...
		 Sets the given file system properties in the root file system of the pool. See
		 zfs(8) Properties for a list of valid properties that can be set.

	 -R root
		 Equivalent to "-o cachefile=none,altroot=root"

	 -m mountpoint
		 Sets the mount point for the root dataset. The default mount point is "/pool" or
		 "altroot/pool" if altroot is specified. The mount point must be an absolute
		 path, "legacy", or "none".  For more information on dataset mount points, see
		 zfs(8).

     zpool destroy [-f] pool

	 Destroys the given pool, freeing up any devices for other use. This command tries to
	 unmount any active datasets before destroying the pool.

	 -f	 Forces any active datasets contained within the pool to be unmounted.

     zpool detach pool device

	 Detaches device from a mirror. The operation is refused if there are no other valid
	 replicas of the data.

     zpool export [-f] pool ...

	 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.

	 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.

	 For pools to be portable, you must give the zpool command whole disks, not just slices,
	 so that ZFS can label the disks with portable EFI labels. Otherwise, disk drivers on
	 platforms of different endianness will not recognize the disks.

	 -f	 Forcefully unmount all datasets, using the "unmount -f" command.

		 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.

     zpool get [-Hp] [-o field[,...]] all | property[,...] pool ...

	 Retrieves the given list of properties (or all properties if "all" is used) for the
	 specified storage pool(s). These properties are displayed with the following fields:

	       name	   Name of storage pool
	       property    Property name
	       value	   Property value
	       source	   Property source, either 'default' or 'local'.

	 See the "Properties" section for more information on the available pool properties.

     -H  Scripted mode. Do not display headers, and separate fields by a single tab instead of
	 arbitrary space.

     -p  Display numbers in parsable (exact) values.

     -o field
	 A comma-separated list of columns to display.	name,property,value,source is the default
	 value.

     zpool history [-il] [pool] ...

	 Displays the command history of the specified pools or all pools if no pool is speci-
	 fied.

	 -i	 Displays internally logged ZFS events in addition to user initiated events.

	 -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.

     zpool import [-d dir | -c cachefile] [-D]

	 Lists pools available to import. If the -d option is not specified, this command
	 searches for devices in "/dev".  The -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 vdev layout and current health of the device for each device or file.
	 Destroyed pools, pools that were previously destroyed with the "zpool destroy" command,
	 are not listed unless the -D option is specified.

	 The numeric identifier is unique, and can be used instead of the pool name when multiple
	 exported pools of the same name are available.

	 -c cachefile
		 Reads configuration from the given cachefile that was created with the
		 "cachefile" pool property. This cachefile is used instead of searching for
		 devices.

	 -d dir  Searches for devices or files in dir.	The -d option can be specified multiple
		 times.

	 -D	 Lists destroyed pools only.

     zpool import [-o mntopts] [-o property=value] ... [-d dir | -c cachefile] [-D] [-f] [-m]
	 [-N] [-R root] [-F [-n]] -a

	 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 "zpool destroy" command,
	 will not be imported unless the -D option is specified.

	 -o mntopts
		 Comma-separated list of mount options to use when mounting datasets within the
		 pool. See zfs(8) for a description of dataset properties and mount options.

	 -o property=value
		 Sets the specified property on the imported pool. See the "Properties" section
		 for more information on the available pool properties.

	 -c cachefile
		 Reads configuration from the given cachefile that was created with the
		 "cachefile" pool property. This cachefile is used instead of searching for
		 devices.

	 -d dir  Searches for devices or files in dir.	The -d option can be specified multiple
		 times. This option is incompatible with the -c option.

	 -D	 Imports destroyed pools only. The -f option is also required.

	 -f	 Forces import, even if the pool appears to be potentially active.

	 -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.

	 -N	 Import the pool without mounting any file systems.

	 -R root
		 Sets the "cachefile" property to "none" and the "altroot" property to "root"

	 -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 dis-
		 carded transactions is irretrievably lost. This option is ignored if the pool is
		 importable or already imported.

	 -n	 Used with the -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 -F option, above.

	 -a	 Searches for and imports all pools found.

     zpool import [-o mntopts] [-o property=value] ... [-d dir | -c cachefile] [-D] [-f] [-m]
	 [-N] [-R root] [-F [-n]] pool | id [newpool]

	 Imports a specific pool. A pool can be identified by its name or the numeric identifier.
	 If newpool is specified, the pool is imported using the name newpool.	Otherwise, it is
	 imported with the same name as its exported name.

	 If a device is removed from a system without running "zpool 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 -f option is required.

	 -o mntopts
		 Comma-separated list of mount options to use when mounting datasets within the
		 pool. See zfs(8) for a description of dataset properties and mount options.

	 -o property=value
		 Sets the specified property on the imported pool. See the "Properties" section
		 for more information on the available pool properties.

	 -c cachefile
		 Reads configuration from the given cachefile that was created with the
		 "cachefile" pool property. This cachefile is used instead of searching for
		 devices.

	 -d dir  Searches for devices or files in dir.	The -d option can be specified multiple
		 times. This option is incompatible with the -c option.

	 -D	 Imports destroyed pools only. The -f option is also required.

	 -f	 Forces import, even if the pool appears to be potentially active.

	 -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.

	 -N	 Import the pool without mounting any file systems.

	 -R root
		 Equivalent to "-o cachefile=none,altroot=root"

	 -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 dis-
		 carded transactions is irretrievably lost. This option is ignored if the pool is
		 importable or already imported.

	 -n	 Used with the -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 -F option, above.

     zpool iostat [-T d|u] [-v] [pool] ... [interval [count]]

	 Displays I/O statistics for the given pools. When given an interval, the statistics are
	 printed every interval seconds until Ctrl-C is pressed. If no pools are specified, sta-
	 tistics for every pool in the system is shown. If count is specified, the command exits
	 after count reports are printed.

	 -T d|u  Print a timestamp.

		 Use modifier d for standard date format. See date(1).	Use modifier u for unix-
		 time (equals "date +%s").

	 -v	 Verbose statistics. Reports usage statistics for individual vdevs within the
		 pool, in addition to the pool-wide statistics.

     zpool labelclear [-f] device

	 Removes ZFS label information from the specified device.  The device must not be part of
	 an active pool configuration.

	 -f	 Treat exported or foreign devices as inactive.

     zpool list [-Hpv] [-o property[,...]] [-T d|u] [pool] ... [inverval [count]]

	 Lists the given pools along with a health status and space usage. If no pools are speci-
	 fied, all pools in the system are listed.

	 When given an interval, the output is printed every interval seconds until Ctrl-C is
	 pressed. If count is specified, the command exits after count reports are printed.

	 -T d|u  Print a timestamp.

		 Use modifier d for standard date format. See date(1).	Use modifier u for unix-
		 time (equals "date +%s").

	 -H	 Scripted mode. Do not display headers, and separate fields by a single tab
		 instead of arbitrary space.

	 -p	 Display numbers in parsable (exact) values.

	 -v	 Verbose statistics. Reports usage statistics for individual vdevs within the
		 pool, in addition to the pool-wide statistics.

	 -o property[,...]
		 Comma-separated list of properties to display. See the "Properties" section for
		 a list of valid properties. The default list is name, size, used, available,
		 fragmentation, expandsize, capacity, health, altroot.

	 -T d|u  Print a timestamp.

		 Use modifier d for standard date format. See date(1).	Use modifier u for unix-
		 time (equals "date +%s").

     zpool offline [-t] pool device ...

	 Takes the specified physical device offline. While the device is offline, no attempt is
	 made to read or write to the device.

	 -t	 Temporary. Upon reboot, the specified physical device reverts to its previous
		 state.

     zpool online [-e] pool device ...

	 Brings the specified physical device online.

	 This command is not applicable to spares or cache devices.

	 -e	 Expand the device to use all available space. If the device is part of a mirror
		 or raidz then all devices must be expanded before the new space will become
		 available to the pool.

     zpool reguid pool

	 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.

     zpool remove pool device ...

	 Removes the specified device from the pool. This command currently only supports remov-
	 ing hot spares, cache, and log devices. A mirrored log device can be removed by specify-
	 ing the top-level mirror for the log. Non-log devices that are part of a mirrored con-
	 figuration can be removed using the "zpool detach" command. Non-redundant and raidz
	 devices cannot be removed from a pool.

     zpool reopen pool

	 Reopen all the vdevs associated with the pool.

     zpool replace [-f] pool device [new_device]

	 Replaces old_device with new_device.  This is equivalent to attaching new_device, wait-
	 ing for it to resilver, and then detaching old_device.

	 The size of new_device must be greater than or equal to the minimum size of all the
	 devices in a mirror or raidz configuration.

	 new_device is required if the pool is not redundant. If new_device is not specified, it
	 defaults to 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
	 /dev path as the old device, even though it is actually a different disk.  ZFS recog-
	 nizes this.

	 -f	 Forces use of new_device, even if its appears to be in use. Not all devices can
		 be overridden in this manner.

     zpool scrub [-s] pool ...

	 Begins a scrub. The scrub examines all data in the specified pools to verify that it
	 checksums correctly. For replicated (mirror or raidz) devices, ZFS automatically repairs
	 any damage discovered during the scrub. The "zpool status" command reports the progress
	 of the scrub and summarizes the results of the scrub upon completion.

	 Scrubbing and resilvering are very similar operations. The difference is that resilver-
	 ing only examines data that 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.

	 Because scrubbing and resilvering are I/O-intensive operations, ZFS only allows one at a
	 time. If a scrub is already in progress, the "zpool scrub" command returns an error. To
	 start a new scrub, you have to stop the old scrub with the "zpool scrub -s" command
	 first. If a resilver is in progress, ZFS does not allow a scrub to be started until the
	 resilver completes.

	 -s	 Stop scrubbing.

     zpool set property=value pool

	 Sets the given property on the specified pool. See the "Properties" section for more
	 information on what properties can be set and acceptable values.

     zpool split [-n] [-R altroot] [-o mntopts] [-o property=value] pool newpool [device ...]

	 Splits off one disk from each mirrored top-level 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 split subcommand chooses the last device
	 in each mirror vdev unless overridden by a device specification on the command line.

	 When using a device argument, split includes the specified device(s) in a new pool and,
	 should any devices remain unspecified, assigns the last device in each mirror vdev to
	 that pool, as it does normally. If you are uncertain about the outcome of a split com-
	 mand, use the -n ("dry-run") option to ensure your command will have the effect you
	 intend.

	 -R altroot
		 Automatically import the newly created pool after splitting, using the specified
		 altroot parameter for the new pool's alternate root. See the altroot description
		 in the "Properties" section, above.

	 -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.

	 -o mntopts
		 Comma-separated list of mount options to use when mounting datasets within the
		 pool. See zfs(8) for a description of dataset properties and mount options.
		 Valid only in conjunction with the -R option.

	 -o property=value
		 Sets the specified property on the new pool. See the "Properties" section,
		 above, for more information on the available pool properties.

     zpool status [-vx] [-T d|u] [pool] ... [interval [count]]

	 Displays the detailed health status for the given pools. If no pool is specified, then
	 the status of each pool in the system is displayed. For more information on pool and
	 device health, see the "Device Failure and Recovery" section.

	 When given an interval, the output is printed every interval seconds until Ctrl-C is
	 pressed. If count is specified, the command exits after count reports are printed.

	 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.

	 -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.

	 -v	 Displays verbose data error information, printing out a complete list of all
		 data errors since the last complete pool scrub.

	 -T d|u  Print a timestamp.

		 Use modifier d for standard date format. See date(1).	Use modifier u for unix-
		 time (equals "date +%s").

     zpool upgrade [-v]

	 Displays pools which do not have all supported features enabled and pools formatted
	 using a legacy ZFS version number.  These pools can continue to be used, but some fea-
	 tures may not be available.  Use zpool upgrade -a to enable all features on all pools.

	 -v	 Displays legacy ZFS versions supported by the current software.  See
		 zpool-features(7) for a description of feature flags features supported by the
		 current software.

     zpool upgrade [-V version] -a | pool ...

	 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
	 zpool-features(7) for details on compatibility with systems that support feature flags,
	 but do not support all features enabled on the pool.

	 -a	 Enables all supported features on all pools.

	 -V version
		 Upgrade to the specified legacy version. If the -V flag is specified, no fea-
		 tures will be enabled on the pool.  This option can only be used to increase
		 version number up to the last supported legacy version number.

EXIT STATUS
     The following exit values are returned:

       0   Successful completion.

       1   An error occurred.

       2   Invalid command line options were specified.

EXAMPLES
     Example 1 Creating a RAID-Z Storage Pool

       The following command creates a pool with a single raidz root vdev that consists of six
       disks.

	 # zpool create tank raidz da0 da1 da2 da3 da4 da5

     Example 2 Creating a Mirrored Storage Pool

       The following command creates a pool with two mirrors, where each mirror contains two
       disks.

	 # zpool create tank mirror da0 da1 mirror da2 da3

     Example 3 Creating a ZFS Storage Pool by Using Partitions

       The following command creates an unmirrored pool using two GPT partitions.

	 # zpool create tank da0p3 da1p3

     Example 4 Creating a ZFS Storage Pool by Using Files

       The following command creates an unmirrored pool using files. While not recommended, a
       pool based on files can be useful for experimental purposes.

	 # zpool create tank /path/to/file/a /path/to/file/b

     Example 5 Adding a Mirror to a ZFS Storage Pool

       The following command adds two mirrored disks to the pool tank, assuming the pool is
       already made up of two-way mirrors. The additional space is immediately available to any
       datasets within the pool.

	 # zpool add tank mirror da2 da3

     Example 6 Listing Available ZFS Storage Pools

       The following command lists all available pools on the system.

	 # 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  -

     Example 7 Listing All Properties for a Pool

       The following command lists all the properties for a pool.

	 # 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	  -

     Example 8 Destroying a ZFS Storage Pool

       The following command destroys the pool "tank" and any datasets contained within.

	 # zpool destroy -f tank

     Example 9 Exporting a ZFS Storage Pool

       The following command exports the devices in pool tank so that they can be relocated or
       later imported.

	 # zpool export tank

     Example 10 Importing a ZFS Storage Pool

       The following command displays available pools, and then imports the pool "tank" for use
       on the system.

       The results from this command are similar to the following:

	 # 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

     Example 11 Upgrading All ZFS Storage Pools to the Current Version

       The following command upgrades all ZFS Storage pools to the current version of the soft-
       ware.

	 # zpool upgrade -a
	 This system is currently running ZFS pool version 28.

     Example 12 Managing Hot Spares

       The following command creates a new pool with an available hot spare:

	 # zpool create tank mirror da0 da1 spare da2

       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:

	 # zpool replace tank da0 da2

       Once the data has been resilvered, the spare is automatically removed and is made avail-
       able should another device fails. The hot spare can be permanently removed from the pool
       using the following command:

	 # zpool remove tank da2

     Example 13 Creating a ZFS Pool with Mirrored Separate Intent Logs

       The following command creates a ZFS storage pool consisting of two, two-way mirrors and
       mirrored log devices:

	 # zpool create pool mirror da0 da1 mirror da2 da3 log mirror da4 da5

     Example 14 Adding Cache Devices to a ZFS Pool

       The following command adds two disks for use as cache devices to a ZFS storage pool:

	 # zpool add pool cache da2 da3

       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 iostat subcommand as follows:

	 # zpool iostat -v pool 5

     Example 15 Displaying expanded space on a device

       The following command dipslays the detailed information for the data pool.  This pool is
       comprised of a single 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 raidz vdev have been expanded.

	 # 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      -      -      -	    -	      -

     Example 16 Removing a Mirrored Log Device

       The following command removes the mirrored log device mirror-2.

       Given this configuration:

	    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

       The command to remove the mirrored log mirror-2 is:

	 # zpool remove tank mirror-2

     Example 17 Recovering a Faulted ZFS Pool

       If a pool is faulted but recoverable, a message indicating this state is provided by
       "zpool status" if the pool was cached (see the -c cachefile argument above), or as part of
       the error output from a failed "zpool import" of the pool.

       Recover a cached pool with the "zpool clear" command:

	 # 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.

       If the pool configuration was not cached, use "zpool import" with the recovery mode flag:

	 # 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.

SEE ALSO
     zpool-features(7), zfs(8)

AUTHORS
     This manual page is a mdoc(7) reimplementation of the OpenSolaris manual page zpool(1M),
     modified and customized for FreeBSD and licensed under the Common Development and Distribu-
     tion License (CDDL).

     The mdoc(7) implementation of this manual page was initially written by Martin Matuska
     <mm@FreeBSD.org>.

CAVEATS
     The spare feature requires a utility to detect zpool degradation and initiate disk replace-
     ment within the zpool.  FreeBSD does not provide such a utility at this time.

BSD					  July 26, 2014 				      BSD
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