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NAME

     zpool — configure ZFS storage pools

SYNOPSIS

     zpool -?V
     zpool add [-fgLnP] [-o property=value] pool vdev...
     zpool attach [-f] [-o property=value] pool device new_device
     zpool checkpoint [-d, --discard] pool
     zpool clear pool [device]
     zpool create [-dfn] [-m mountpoint] [-o property=value]... [-o feature@feature=value] [-O
           file-system-property=value]... [-R root] pool vdev...
     zpool destroy [-f] pool
     zpool detach pool device
     zpool events [-vHf [pool] | -c]
     zpool export [-a] [-f] pool...
     zpool get [-Hp] [-o field[,field]...] all|property[,property]... [pool]...
     zpool history [-il] [pool]...
     zpool import [-D] [-d dir|device]
     zpool import -a [-DflmN] [-F [-n] [-T] [-X]] [--rewind-to-checkpoint]
           [-c cachefile|-d dir|device] [-o mntopts] [-o property=value]... [-R root]
     zpool import [-Dflm] [-F [-n] [-T] [-X]] [--rewind-to-checkpoint]
           [-c cachefile|-d dir|device] [-o mntopts] [-o property=value]... [-R root] [-s]
           pool|id [newpool [-t]]
     zpool initialize [-c | -s] pool [device...]
     zpool iostat [[[-c SCRIPT] [-lq]]|-rw] [-T u|d] [-ghHLnpPvy] [[pool...]|[pool
           vdev...]|[vdev...]] [interval [count]]
     zpool labelclear [-f] device
     zpool list [-HgLpPv] [-o property[,property]...] [-T u|d] [pool]... [interval [count]]
     zpool offline [-f] [-t] pool device...
     zpool online [-e] pool device...
     zpool reguid pool
     zpool reopen [-n] pool
     zpool remove [-np] pool device...
     zpool remove -s pool
     zpool replace [-f] [-o property=value] pool device [new_device]
     zpool resilver pool...
     zpool scrub [-s | -p] pool...
     zpool trim [-d] [-r rate] [-c | -s] pool [device...]
     zpool set property=value pool
     zpool split [-gLlnP] [-o property=value]... [-R root] pool newpool [device]...
     zpool status [-c SCRIPT] [-DigLpPstvx] [-T u|d] [pool]... [interval [count]]
     zpool sync [pool]...
     zpool upgrade
     zpool upgrade -v
     zpool upgrade [-V version] -a|pool...
     zpool version

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 managing datasets.

   Virtual Devices (vdevs)
     A "virtual device" 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
             partitions, though the recommended mode of operation is to use whole disks.  A disk
             can be specified by a full path, or it can be a shorthand name (the relative portion
             of the path under /dev).  A whole disk can be specified by omitting the slice or
             partition designation.  For example, sda is equivalent to /dev/sda.  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 as 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, raidz1, raidz2, raidz3
             A variation on RAID-5 that allows for better distribution 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
             compromised.  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
             performance.

     spare   A 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.

     dedup   A device dedicated solely for deduplication tables.  The redundancy of this device
             should match the redundancy of the other normal devices in the pool. If more than
             one dedup device is specified, then allocations are load-balanced between those
             devices.

     special
             A device dedicated solely for allocating various kinds of internal metadata, and
             optionally small file blocks.  The redundancy of this device should match the
             redundancy of the other normal devices in the pool. If more than one special device
             is specified, then allocations are load-balanced between those devices.

             For more information on special allocations, see the Special Allocation Class
             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 sda sdb mirror sdc sdd

   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
     redundancy, 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
     replicas 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:

               ·   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.

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

     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:

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

               ·   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
               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.

     If a device is removed and later re-attached to the system, ZFS attempts to put the device
     online automatically.  Device attach detection is hardware-dependent and might not be
     supported 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 sda sdb spare sdc sdd

     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.

     Shared spares add some risk.  If the pools are imported on different hosts, and both pools
     suffer a device failure at the same time, both could attempt to use the spare at the same
     time.  This may not be detected, resulting in data corruption.

     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.

     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 sda sdb log sdc

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

     Log devices can be added, replaced, attached, detached and removed.  In addition, log
     devices are imported and exported as part of the pool that contains them.  Mirrored devices
     can be removed by specifying the top-level mirror vdev.

   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.

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

     # zpool create pool sda sdb cache sdc sdd

     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.

   Pool checkpoint
     Before starting critical procedures that include destructive actions (e.g zfs destroy ), an
     administrator can checkpoint the pool's state and in the case of a mistake or failure,
     rewind the entire pool back to the checkpoint.  Otherwise, the checkpoint can be discarded
     when the procedure has completed successfully.

     A pool checkpoint can be thought of as a pool-wide snapshot and should be used with care as
     it contains every part of the pool's state, from properties to vdev configuration.  Thus,
     while a pool has a checkpoint certain operations are not allowed.  Specifically, vdev
     removal/attach/detach, mirror splitting, and changing the pool's guid.  Adding a new vdev is
     supported but in the case of a rewind it will have to be added again.  Finally, users of
     this feature should keep in mind that scrubs in a pool that has a checkpoint do not repair
     checkpointed data.

     To create a checkpoint for a pool:

     # zpool checkpoint pool

     To later rewind to its checkpointed state, you need to first export it and then rewind it
     during import:

     # zpool export pool
     # zpool import --rewind-to-checkpoint pool

     To discard the checkpoint from a pool:

     # zpool checkpoint -d pool

     Dataset reservations (controlled by the reservation or refreservation zfs properties) may be
     unenforceable while a checkpoint exists, because the checkpoint is allowed to consume the
     dataset's reservation.  Finally, data that is part of the checkpoint but has been freed in
     the current state of the pool won't be scanned during a scrub.

   Special Allocation Class
     The allocations in the special class are dedicated to specific block types.  By default this
     includes all metadata, the indirect blocks of user data, and any deduplication tables.  The
     class can also be provisioned to accept small file blocks.

     A pool must always have at least one normal (non-dedup/special) vdev before other devices
     can be assigned to the special class. If the special class becomes full, then allocations
     intended for it will spill back into the normal class.

     Deduplication tables can be excluded from the special class by setting the
     zfs_ddt_data_is_special zfs module parameter to false (0).

     Inclusion of small file blocks in the special class is opt-in. Each dataset can control the
     size of small file blocks allowed in the special class by setting the special_small_blocks
     dataset property. It defaults to zero, so you must opt-in by setting it to a non-zero value.
     See zfs(8) for more info on setting this property.

   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:

     allocated
             Amount of storage used within the pool.  See fragmentation and free for more
             information.

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

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

     fragmentation
             The amount of fragmentation in the pool. As the amount of space allocated increases,
             it becomes more difficult to locate free space. This may result in lower write
             performance compared to pools with more unfragmented free space.

     free    The amount of free space available in the pool.  By contrast, the zfs(8) available
             property describes how much new data can be written to ZFS filesystems/volumes.  The
             zpool free property is not generally useful for this purpose, and can be
             substantially more than the zfs available space. This discrepancy is due to several
             factors, including raidz party; zfs reservation, quota, refreservation, and refquota
             properties; and space set aside by spa_slop_shift (see zfs-module-parameters(5) for
             more information).

     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.

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

     guid    A unique identifier for the pool.

     load_guid
             A unique identifier for the pool.  Unlike the guid property, this identifier is
             generated every time we load the pool (e.g. does not persist across imports/exports)
             and never changes while the pool is loaded (even if a reguid operation takes place).

     size    Total size of the storage pool.

     unsupported@feature_guid
             Information about unsupported features that are enabled on the pool.  See
             zpool-features(5) for details.

     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
     characteristics 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 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 be set only at import time:

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

     ashift=ashift
             Pool sector size exponent, to the power of 2 (internally referred to as ashift ).
             Values from 9 to 16, inclusive, are valid; also, the value 0 (the default) means to
             auto-detect using the kernel's block layer and a ZFS internal exception list. I/O
             operations will be aligned to the specified size boundaries. Additionally, the
             minimum (disk) write size will be set to the specified size, so this represents a
             space vs. performance trade-off. For optimal performance, the pool sector size
             should be greater than or equal to the sector size of the underlying disks. The
             typical case for setting this property is when performance is important and the
             underlying disks use 4KiB sectors but report 512B sectors to the OS (for
             compatibility reasons); in that case, set ashift=12 (which is 1<<12 = 4096). When
             set, this property is used as the default hint value in subsequent vdev operations
             (add, attach and replace). Changing this value will not modify any existing vdev,
             not even on disk replacement; however it can be used, for instance, to replace a
             dying 512B sectors disk with a newer 4KiB sectors device: this will probably result
             in bad performance but at the same time could prevent loss of data.

     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
             initiated 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.  Autoreplace can also be used with virtual disks (like device mapper)
             provided that you use the /dev/disk/by-vdev paths setup by vdev_id.conf. See the
             vdev_id(8) man page for more details.  Autoreplace and autoonline require the ZFS
             Event Daemon be configured and running.  See the zed(8) man page for more details.

     bootfs=(unset)|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.  Not all Linux
             distribution boot processes use the bootfs property.

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

             Multiple pools can share the same cache file.  Because the kernel destroys and
             recreates this file when pools are added and removed, care should be taken when
             attempting to access this file.  When the last pool using a cachefile is exported or
             destroyed, the file will be empty.

     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
             This property is deprecated.  In a future release, it will no longer have any
             effect.

             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.  The default setting is 0 which causes no ditto copies to be
             created for deduplicated blocks.  The minimum legal nonzero setting is 100.

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

     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
                       remaining 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.

     autotrim=on|off
             When set to on space which has been recently freed, and is no longer allocated by
             the pool, will be periodically trimmed.  This allows block device vdevs which
             support BLKDISCARD, such as SSDs, or file vdevs on which the underlying file system
             supports hole-punching, to reclaim unused blocks.  The default setting for this
             property is off.

             Automatic TRIM does not immediately reclaim blocks after a free. Instead, it will
             optimistically delay allowing smaller ranges to be aggregated in to a few larger
             ones.  These can then be issued more efficiently to the storage.

             Be aware that automatic trimming of recently freed data blocks can put significant
             stress on the underlying storage devices.  This will vary depending of how well the
             specific device handles these commands.  For lower end devices it is often possible
             to achieve most of the benefits of automatic trimming by running an on-demand
             (manual) TRIM periodically using the zpool trim command.

     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(5) for details on feature states.

     listsnapshots=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.  This
             property can also be referred to by its shortened name, listsnaps.

     multihost=on|off
             Controls whether a pool activity check should be performed during zpool import.
             When a pool is determined to be active it cannot be imported, even with the -f
             option.  This property is intended to be used in failover configurations where
             multiple hosts have access to a pool on shared storage.

             Multihost provides protection on import only.  It does not protect against an
             individual device being used in multiple pools, regardless of the type of vdev.  See
             the discussion under zpool create.

             When this property is on, periodic writes to storage occur to show the pool is in
             use.  See zfs_multihost_interval in the zfs-module-parameters(5) man page.  In order
             to enable this property each host must set a unique hostid.  See genhostid(1)
             zgenhostid(8) spl-module-parameters(5) for additional details.  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 are 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 -V, --version
             An alias for the zpool version subcommand.

     zpool add [-fgLnP] [-o property=value] 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 vdevs, even if they appear in use or specify a conflicting
                     replication level.  Not all devices can be overridden in this manner.

             -g      Display vdev, GUIDs instead of the normal device names. These GUIDs can be
                     used in place of device names for the zpool detach/offline/remove/replace
                     commands.

             -L      Display real paths for vdevs resolving all symbolic links. This can be used
                     to look up the current block device name regardless of the /dev/disk/ path
                     used to open it.

             -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.

             -P      Display real paths for vdevs instead of only the last component of the path.
                     This can be used in conjunction with the -L flag.

             -o property=value
                     Sets the given pool properties. See the Properties section for a list of
                     valid properties that can be set. The only property supported at the moment
                     is ashift.

     zpool attach [-f] [-o property=value] pool device new_device
             Attaches new_device to the existing 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 it appears to be in use.  Not all devices
                     can be overridden in this manner.

             -o property=value
                     Sets the given pool properties. See the Properties section for a list of
                     valid properties that can be set. The only property supported at the moment
                     is ashift.

     zpool checkpoint [-d, --discard] pool
             Checkpoints the current state of pool , which can be later restored by zpool import
             --rewind-to-checkpoint.  The existence of a checkpoint in a pool prohibits the
             following zpool commands: remove, attach, detach, split, and reguid.  In addition,
             it may break reservation boundaries if the pool lacks free space.  The zpool status
             command indicates the existence of a checkpoint or the progress of discarding a
             checkpoint from a pool.  The zpool list command reports how much space the
             checkpoint takes from the pool.

             -d, --discard
                     Discards an existing checkpoint from pool.

     zpool clear 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.  If multihost is
             enabled, and the pool has been suspended, this will not resume I/O.  While the pool
             was suspended, it may have been imported on another host, and resuming I/O could
             result in pool damage.

     zpool create [-dfn] [-m mountpoint] [-o property=value]... [-o feature@feature=value]... [-O
             file-system-property=value]... [-R root] [-t tname] 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 ("-"), colon (":"), space (" "), and
             period (".").  The pool names mirror, raidz, spare and log are reserved, as are
             names beginning with mirror, raidz, spare, and the pattern c[0-9].  The vdev
             specification is described in the Virtual Devices section.

             The command attempts to verify that each device specified is accessible and not
             currently in use by another subsystem.  However this check is not robust enough to
             detect simultaneous attempts to use a new device in different pools, even if
             multihost is enabled. The administrator must ensure that simultaneous invocations of
             any combination of zpool replace, zpool create, zpool add, or zpool labelclear, do
             not refer to the same device.  Using the same device in two pools will result in
             pool corruption.

             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.

             -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(5) for details about feature properties.

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

             -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).

             -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.

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

             -o feature@feature=value
                     Sets the given pool feature. See the zpool-features(5) section for a list of
                     valid features that can be set.  Value can be either disabled or enabled.

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

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

             -t tname
                     Sets the in-core pool name to tname while the on-disk name will be the name
                     specified as the pool name pool.  This will set the default cachefile
                     property to none. This is intended to handle name space collisions when
                     creating pools for other systems, such as virtual machines or physical
                     machines whose pools live on network block devices.

     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.  If device may be re-added to the pool later on then consider
             the zpool offline command instead.

     zpool events [-vHf [pool] | -c]
             Lists all recent events generated by the ZFS kernel modules.  These events are
             consumed by the zed(8) and used to automate administrative tasks such as replacing a
             failed device with a hot spare. For more information about the subclasses and event
             payloads that can be generated see the zfs-events(5) man page.

             -c      Clear all previous events.

             -f      Follow mode.

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

             -v      Print the entire payload for each event.

     zpool export [-a] [-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
             partitions, so that ZFS can label the disks with portable EFI labels.  Otherwise,
             disk drivers on platforms of different endianness will not recognize the disks.

             -a      Exports all pools imported on the system.

             -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[,field]...] all|property[,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.

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

             -p      Display numbers in parsable (exact) values.

     zpool history [-il] [pool]...
             Displays the command history of the specified pool(s) or all pools if no pool is
             specified.

             -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] [-d dir|device]
             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|device
                     Uses device or searches for devices or files in dir.  The -d option can be
                     specified multiple times.

             -D      Lists destroyed pools only.

     zpool import -a [-DflmN] [-F [-n] [-T] [-X]] [-c cachefile|-d dir|device] [-o mntopts] [-o
             property=value]... [-R root] [-s]
             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.

             -a      Searches for and imports all pools found.

             -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|device
                     Uses device or 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.

             -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.

             -l      Indicates that this command will request encryption keys for all encrypted
                     datasets it attempts to mount as it is bringing the pool online. Note that
                     if any datasets have a keylocation of prompt this command will block waiting
                     for the keys to be entered. Without this flag encrypted datasets will be
                     left unavailable until the keys are loaded.

             -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      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.

             -N      Import the pool without mounting any file systems.

             -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.

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

             --rewind-to-checkpoint
                     Rewinds pool to the checkpointed state.  Once the pool is imported with this
                     flag there is no way to undo the rewind.  All changes and data that were
                     written after the checkpoint are lost!  The only exception is when the
                     readonly mounting option is enabled.  In this case, the checkpointed state
                     of the pool is opened and an administrator can see how the pool would look
                     like if they were to fully rewind.

             -s      Scan using the default search path, the libblkid cache will not be
                     consulted. A custom search path may be specified by setting the
                     ZPOOL_IMPORT_PATH environment variable.

             -X      Used with the -F recovery option. Determines whether extreme measures to
                     find a valid txg should take place. This allows the pool to be rolled back
                     to a txg which is no longer guaranteed to be consistent.  Pools imported at
                     an inconsistent txg may contain uncorrectable checksum errors. For more
                     details about pool recovery mode, see the -F option, above. WARNING: This
                     option can be extremely hazardous to the health of your pool and should only
                     be used as a last resort.

             -T      Specify the txg to use for rollback. Implies -FX.  For more details about
                     pool recovery mode, see the -X option, above. WARNING: This option can be
                     extremely hazardous to the health of your pool and should only be used as a
                     last resort.

     zpool import [-Dflm] [-F [-n] [-t] [-T] [-X]] [-c cachefile|-d dir|device] [-o mntopts] [-o
             property=value]... [-R root] [-s] 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.

             -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|device
                     Uses device or 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 pool.  The -f option is also required.

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

             -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.

             -l      Indicates that this command will request encryption keys for all encrypted
                     datasets it attempts to mount as it is bringing the pool online. Note that
                     if any datasets have a keylocation of prompt this command will block waiting
                     for the keys to be entered. Without this flag encrypted datasets will be
                     left unavailable until the keys are loaded.

             -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      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.

             -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.

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

             -s      Scan using the default search path, the libblkid cache will not be
                     consulted. A custom search path may be specified by setting the
                     ZPOOL_IMPORT_PATH environment variable.

             -X      Used with the -F recovery option. Determines whether extreme measures to
                     find a valid txg should take place. This allows the pool to be rolled back
                     to a txg which is no longer guaranteed to be consistent.  Pools imported at
                     an inconsistent txg may contain uncorrectable checksum errors. For more
                     details about pool recovery mode, see the -F option, above. WARNING: This
                     option can be extremely hazardous to the health of your pool and should only
                     be used as a last resort.

             -T      Specify the txg to use for rollback. Implies -FX.  For more details about
                     pool recovery mode, see the -X option, above. WARNING: This option can be
                     extremely hazardous to the health of your pool and should only be used as a
                     last resort.

             -t      Used with newpool.  Specifies that newpool is temporary. Temporary pool
                     names last until export. Ensures that the original pool name will be used in
                     all label updates and therefore is retained upon export.  Will also set -o
                     cachefile=none when not explicitly specified.

     zpool initialize [-c | -s] pool [device...]
             Begins initializing by writing to all unallocated regions on the specified devices,
             or all eligible devices in the pool if no individual devices are specified.  Only
             leaf data or log devices may be initialized.

             -c, --cancel
                     Cancel initializing on the specified devices, or all eligible devices if
                     none are specified.  If one or more target devices are invalid or are not
                     currently being initialized, the command will fail and no cancellation will
                     occur on any device.

             -s --suspend
                     Suspend initializing on the specified devices, or all eligible devices if
                     none are specified.  If one or more target devices are invalid or are not
                     currently being initialized, the command will fail and no suspension will
                     occur on any device.  Initializing can then be resumed by running zpool
                     initialize with no flags on the relevant target devices.

     zpool iostat [[[-c SCRIPT] [-lq]]|-rw] [-T u|d] [-ghHLnpPvy] [[pool...]|[pool
             vdev...]|[vdev...]] [interval [count]]
             Displays logical I/O statistics for the given pools/vdevs. Physical I/Os may be
             observed via iostat(1).  If writes are located nearby, they may be merged into a
             single larger operation. Additional I/O may be generated depending on the level of
             vdev redundancy.  To filter output, you may pass in a list of pools, a pool and list
             of vdevs in that pool, or a list of any vdevs from any pool. If no items are
             specified, statistics for every pool in the system are shown.  When given an
             interval, the statistics are printed every interval seconds until ^C is pressed. If
             -n flag is specified the headers are displayed only once, otherwise they are
             displayed periodically. If count is specified, the command exits after count reports
             are printed. The first report printed is always the statistics since boot regardless
             of whether interval and count are passed. However, this behavior can be suppressed
             with the -y flag. Also note that the units of K, M, G ... that are printed in the
             report are in base 1024. To get the raw values, use the -p flag.

             -c [SCRIPT1[,SCRIPT2]...]
                     Run a script (or scripts) on each vdev and include the output as a new
                     column in the zpool iostat output. Users can run any script found in their
                     ~/.zpool.d directory or from the system /etc/zfs/zpool.d directory. Script
                     names containing the slash (/) character are not allowed.  The default
                     search path can be overridden by setting the ZPOOL_SCRIPTS_PATH environment
                     variable. A privileged user can run -c if they have the
                     ZPOOL_SCRIPTS_AS_ROOT environment variable set. If a script requires the use
                     of a privileged command, like smartctl(8), then it's recommended you allow
                     the user access to it in /etc/sudoers or add the user to the
                     /etc/sudoers.d/zfs file.

                     If -c is passed without a script name, it prints a list of all scripts.  -c
                     also sets verbose mode (-v).

                     Script output should be in the form of "name=value". The column name is set
                     to "name" and the value is set to "value". Multiple lines can be used to
                     output multiple columns. The first line of output not in the "name=value"
                     format is displayed without a column title, and no more output after that is
                     displayed. This can be useful for printing error messages. Blank or NULL
                     values are printed as a '-' to make output awk-able.

                     The following environment variables are set before running each script:

                     VDEV_PATH  Full path to the vdev

                     VDEV_UPATH  Underlying path to the vdev (/dev/sd*).  For use with device
                                 mapper, multipath, or partitioned vdevs.

                     VDEV_ENC_SYSFS_PATH  The sysfs path to the enclosure for the vdev (if any).

             -T u|d  Display a time stamp.  Specify u for a printed representation of the
                     internal representation of time.  See time(2).  Specify d for standard date
                     format.  See date(1).

             -g      Display vdev GUIDs instead of the normal device names. These GUIDs can be
                     used in place of device names for the zpool detach/offline/remove/replace
                     commands.

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

             -L      Display real paths for vdevs resolving all symbolic links. This can be used
                     to look up the current block device name regardless of the /dev/disk/ path
                     used to open it.

             -n      Print headers only once when passed

             -p      Display numbers in parsable (exact) values. Time values are in nanoseconds.

             -P      Display full paths for vdevs instead of only the last component of the path.
                     This can be used in conjunction with the -L flag.

             -r      Print request size histograms for the leaf vdev's IO. This includes
                     histograms of individual IOs (ind) and aggregate IOs (agg). These stats can
                     be useful for observing how well IO aggregation is working.  Note that TRIM
                     IOs may exceed 16M, but will be counted as 16M.

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

             -y      Omit statistics since boot.  Normally the first line of output reports the
                     statistics since boot.  This option suppresses that first line of output.
                     interval

             -w      Display latency histograms:

                     total_wait: Total IO time (queuing + disk IO time).  disk_wait: Disk IO time
                     (time reading/writing the disk).  syncq_wait: Amount of time IO spent in
                     synchronous priority queues.  Does not include disk time.  asyncq_wait:
                     Amount of time IO spent in asynchronous priority queues.  Does not include
                     disk time.  scrub: Amount of time IO spent in scrub queue. Does not include
                     disk time.

             -l      Include average latency statistics:

                     total_wait: Average total IO time (queuing + disk IO time).  disk_wait:
                     Average disk IO time (time reading/writing the disk).  syncq_wait: Average
                     amount of time IO spent in synchronous priority queues. Does not include
                     disk time.  asyncq_wait: Average amount of time IO spent in asynchronous
                     priority queues.  Does not include disk time.  scrub: Average queuing time
                     in scrub queue. Does not include disk time.  trim: Average queuing time in
                     trim queue. Does not include disk time.

             -q      Include active queue statistics. Each priority queue has both pending (
                     pend) and active ( activ) IOs. Pending IOs are waiting to be issued to the
                     disk, and active IOs have been issued to disk and are waiting for
                     completion. These stats are broken out by priority queue:

                     syncq_read/write: Current number of entries in synchronous priority queues.
                     asyncq_read/write: Current number of entries in asynchronous priority
                     queues.  scrubq_read: Current number of entries in scrub queue.
                     trimq_write: Current number of entries in trim queue.

                     All queue statistics are instantaneous measurements of the number of entries
                     in the queues. If you specify an interval, the measurements will be sampled
                     from the end of the interval.

     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 [-HgLpPv] [-o property[,property]...] [-T u|d] [pool]... [interval [count]]
             Lists the given pools along with a health status and space usage.  If no pools are
             specified, all pools in the system are listed.  When given an interval, the
             information is printed every interval seconds until ^C is pressed.  If count is
             specified, the command exits after count reports are printed.

             -g      Display vdev GUIDs instead of the normal device names. These GUIDs can be
                     used in place of device names for the zpool detach/offline/remove/replace
                     commands.

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

             -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, allocated,
                     free, checkpoint, expandsize, fragmentation, capacity, dedupratio, health,
                     altroot.

             -L      Display real paths for vdevs resolving all symbolic links. This can be used
                     to look up the current block device name regardless of the /dev/disk/ path
                     used to open it.

             -p      Display numbers in parsable (exact) values.

             -P      Display full paths for vdevs instead of only the last component of the path.
                     This can be used in conjunction with the -L flag.

             -T u|d  Display a time stamp.  Specify u for a printed representation of the
                     internal representation of time.  See time(2).  Specify d for standard date
                     format.  See date(1).

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

     zpool offline [-f] [-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.  This command is not applicable to
             spares.

             -f      Force fault. Instead of offlining the disk, put it into a faulted state. The
                     fault will persist across imports unless the -t flag was specified.

             -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.

             -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 reopen [-n] pool
             Reopen all the vdevs associated with the pool.

             -n      Do not restart an in-progress scrub operation. This is not recommended and
                     can result in partially resilvered devices unless a second scrub is
                     performed.

     zpool remove [-np] pool device...
             Removes the specified device from the pool.  This command supports removing hot
             spare, cache, log, and both mirrored and non-redundant primary top-level vdevs,
             including dedup and special vdevs.  When the primary pool storage includes a top-
             level raidz vdev only hot spare, cache, and log devices can be removed.

             Removing a top-level vdev reduces the total amount of space in the storage pool.
             The specified device will be evacuated by copying all allocated space from it to the
             other devices in the pool.  In this case, the zpool remove command initiates the
             removal and returns, while the evacuation continues in the background.  The removal
             progress can be monitored with zpool status.  If an IO error is encountered during
             the removal process it will be cancelled. The device_removal feature flag must be
             enabled to remove a top-level vdev, see zpool-features(5).

             A mirrored top-level device (log or data) can be removed by specifying the top-level
             mirror for the same.  Non-log devices or data devices that are part of a mirrored
             configuration can be removed using the zpool detach command.

             -n      Do not actually perform the removal ("no-op").  Instead, print the estimated
                     amount of memory that will be used by the mapping table after the removal
                     completes.  This is nonzero only for top-level vdevs.

             -p      Used in conjunction with the -n flag, displays numbers as parsable (exact)
                     values.

     zpool remove -s pool
             Stops and cancels an in-progress removal of a top-level vdev.

     zpool replace [-f] [-o property=value] pool device [new_device]
             Replaces old_device with new_device.  This is equivalent to attaching new_device,
             waiting 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 recognizes this.

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

             -o property=value
                     Sets the given pool properties. See the Properties section for a list of
                     valid properties that can be set.  The only property supported at the moment
                     is ashift.

     zpool scrub [-s | -p] pool...
             Begins a scrub or resumes a paused scrub.  The scrub examines all data in the
             specified pools to verify that it checksums correctly.  For replicated (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
             resilvering 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 paused, the zpool scrub resumes it.  If a resilver is in
             progress, ZFS does not allow a scrub to be started until the resilver completes.

             Note that, due to changes in pool data on a live system, it is possible for scrubs
             to progress slightly beyond 100% completion. During this period, no completion time
             estimate will be provided.

             -s      Stop scrubbing.

             -p      Pause scrubbing.  Scrub pause state and progress are periodically synced to
                     disk.  If the system is restarted or pool is exported during a paused scrub,
                     even after import, scrub will remain paused until it is resumed.  Once
                     resumed the scrub will pick up from the place where it was last checkpointed
                     to disk.  To resume a paused scrub issue zpool scrub again.

     zpool resilver pool...
             Starts a resilver. If an existing resilver is already running it will be restarted
             from the beginning. Any drives that were scheduled for a deferred resilver will be
             added to the new one. This requires the resilver_defer feature.

     zpool trim [-d] [-c | -s] pool [device...]
             Initiates an immediate on-demand TRIM operation for all of the free space in a pool.
             This operation informs the underlying storage devices of all blocks in the pool
             which are no longer allocated and allows thinly provisioned devices to reclaim the
             space.

             A manual on-demand TRIM operation can be initiated irrespective of the autotrim pool
             property setting.  See the documentation for the autotrim property above for the
             types of vdev devices which can be trimmed.

             -d --secure
                     Causes a secure TRIM to be initiated.  When performing a secure TRIM, the
                     device guarantees that data stored on the trimmed blocks has been erased.
                     This requires support from the device and is not supported by all SSDs.

             -r --rate rate
                     Controls the rate at which the TRIM operation progresses.  Without this
                     option TRIM is executed as quickly as possible. The rate, expressed in bytes
                     per second, is applied on a per-vdev basis and may be set differently for
                     each leaf vdev.

             -c, --cancel
                     Cancel trimming on the specified devices, or all eligible devices if none
                     are specified.  If one or more target devices are invalid or are not
                     currently being trimmed, the command will fail and no cancellation will
                     occur on any device.

             -s --suspend
                     Suspend trimming on the specified devices, or all eligible devices if none
                     are specified.  If one or more target devices are invalid or are not
                     currently being trimmed, the command will fail and no suspension will occur
                     on any device.  Trimming can then be resumed by running zpool trim with no
                     flags on the relevant target devices.

     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 [-gLlnP] [-o property=value]... [-R root] pool newpool [device ...]
             Splits devices off pool creating newpool.  All vdevs in pool must be mirrors and the
             pool must not be in the process of resilvering.  At the time of the split, newpool
             will be a replica of pool.  By default, the last device in each mirror is split from
             pool to create newpool.

             The optional device specification causes the specified device(s) to be included in
             the new pool and, should any devices remain unspecified, the last device in each
             mirror is used as would be by default.

             -g      Display vdev GUIDs instead of the normal device names. These GUIDs can be
                     used in place of device names for the zpool detach/offline/remove/replace
                     commands.

             -L      Display real paths for vdevs resolving all symbolic links. This can be used
                     to look up the current block device name regardless of the /dev/disk/ path
                     used to open it.

             -l      Indicates that this command will request encryption keys for all encrypted
                     datasets it attempts to mount as it is bringing the new pool online. Note
                     that if any datasets have a keylocation of prompt this command will block
                     waiting for the keys to be entered. Without this flag encrypted datasets
                     will be left unavailable until the keys are loaded.

             -n      Do dry run, do not actually perform the split.  Print out the expected
                     configuration of newpool.

             -P      Display full paths for vdevs instead of only the last component of the path.
                     This can be used in conjunction with the -L flag.

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

             -R root
                     Set altroot for newpool to root and automatically import it.

     zpool status [-c [SCRIPT1[,SCRIPT2]...]] [-DigLpPstvx] [-T u|d] [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.

             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.

             -c [SCRIPT1[,SCRIPT2]...]
                     Run a script (or scripts) on each vdev and include the output as a new
                     column in the zpool status output.  See the -c option of zpool iostat for
                     complete details.

             -i      Display vdev initialization status.

             -g      Display vdev GUIDs instead of the normal device names. These GUIDs can be
                     used in place of device names for the zpool detach/offline/remove/replace
                     commands.

             -L      Display real paths for vdevs resolving all symbolic links. This can be used
                     to look up the current block device name regardless of the /dev/disk/ path
                     used to open it.

             -p      Display numbers in parsable (exact) values.

             -P      Display full paths for vdevs instead of only the last component of the path.
                     This can be used in conjunction with the -L flag.

             -D      Display a histogram of deduplication statistics, showing the allocated
                     (physically present on disk) and referenced (logically referenced in the
                     pool) block counts and sizes by reference count.

             -s      Display the number of leaf VDEV slow IOs.  This is the number of IOs that
                     didn't complete in zio_slow_io_ms milliseconds (default 30 seconds).  This
                     does not necessarily mean the IOs failed to complete, just took an
                     unreasonably long amount of time.  This may indicate a problem with the
                     underlying storage.

             -t      Display vdev TRIM status.

             -T u|d  Display a time stamp.  Specify u for a printed representation of the
                     internal representation of time.  See time(2).  Specify d for standard date
                     format.  See date(1).

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

             -x      Only display status for pools that are exhibiting errors or are otherwise
                     unavailable.  Warnings about pools not using the latest on-disk format will
                     not be included.

     zpool sync [pool ...]
             This command forces all in-core dirty data to be written to the primary pool storage
             and not the ZIL. It will also update administrative information including quota
             reporting. Without arguments, zpool sync will sync all pools on the system.
             Otherwise, it will sync only the specified pool(s).

     zpool upgrade
             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
             features may not be available.  Use zpool upgrade -a to enable all features on all
             pools.

     zpool upgrade -v
             Displays legacy ZFS versions supported by the current software.  See
             zpool-features(5) 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(5) 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
                     features will be enabled on the pool.  This option can only be used to
                     increase the version number up to the last supported legacy version number.

     zpool version
             Displays the software version of the zpool userland utility and the zfs kernel
             module.

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 sda sdb sdc sdd sde sdf

     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 sda sdb mirror sdc sdd

     Example 3 Creating a ZFS Storage Pool by Using Partitions
             The following command creates an unmirrored pool using two disk partitions.

             # zpool create tank sda1 sdb2

     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 sda sdb

     Example 6 Listing Available ZFS Storage Pools
             The following command lists all available pools on the system.  In this case, the
             pool zion is faulted due to a missing device.  The results from this command are
             similar to the following:

             # zpool list
             NAME    SIZE  ALLOC   FREE  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
             rpool  19.9G  8.43G  11.4G         -    33%    42%  1.00x  ONLINE  -
             tank   61.5G  20.0G  41.5G         -    48%    32%  1.00x  ONLINE  -
             zion       -      -      -         -      -      -      -  FAULTED -

     Example 7 Destroying a ZFS Storage Pool
             The following command destroys the pool tank and any datasets contained within.

             # zpool destroy -f tank

     Example 8 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 9 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
                         sda     ONLINE
                         sdb     ONLINE

             # zpool import tank

     Example 10 Upgrading All ZFS Storage Pools to the Current Version
             The following command upgrades all ZFS Storage pools to the current version of the
             software.

             # zpool upgrade -a
             This system is currently running ZFS version 2.

     Example 11 Managing Hot Spares
             The following command creates a new pool with an available hot spare:

             # zpool create tank mirror sda sdb spare sdc

             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 sda sdd

             Once the data has been resilvered, the spare is automatically removed and is made
             available for use should another device fail.  The hot spare can be permanently
             removed from the pool using the following command:

             # zpool remove tank sdc

     Example 12 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 sda sdb mirror sdc sdd log mirror \
               sde sdf

     Example 13 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 sdc sdd

             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 option as follows:

             # zpool iostat -v pool 5

     Example 14 Removing a Mirrored top-level (Log or Data) Device
             The following commands remove the mirrored log device mirror-2 and mirrored top-
             level data device mirror-1.

             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
                          sda     ONLINE       0     0     0
                          sdb     ONLINE       0     0     0
                        mirror-1  ONLINE       0     0     0
                          sdc     ONLINE       0     0     0
                          sdd     ONLINE       0     0     0
                      logs
                        mirror-2  ONLINE       0     0     0
                          sde     ONLINE       0     0     0
                          sdf     ONLINE       0     0     0

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

             # zpool remove tank mirror-2

             The command to remove the mirrored data mirror-1 is:

             # zpool remove tank mirror-1

     Example 15 Displaying expanded space on a device
             The following command displays the detailed information for the pool data.  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 utilize this extra
             capacity until all the devices under the raidz vdev have been expanded.

             # zpool list -v data
             NAME         SIZE  ALLOC   FREE  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
             data        23.9G  14.6G  9.30G         -    48%    61%  1.00x  ONLINE  -
               raidz1    23.9G  14.6G  9.30G         -    48%
                 sda         -      -      -         -      -
                 sdb         -      -      -       10G      -
                 sdc         -      -      -         -      -

     Example 16 Adding output columns
             Additional columns can be added to the zpool status and zpool iostat output with -c
             option.

             # zpool status -c vendor,model,size
                NAME     STATE  READ WRITE CKSUM vendor  model        size
                tank     ONLINE 0    0     0
                mirror-0 ONLINE 0    0     0
                U1       ONLINE 0    0     0     SEAGATE ST8000NM0075 7.3T
                U10      ONLINE 0    0     0     SEAGATE ST8000NM0075 7.3T
                U11      ONLINE 0    0     0     SEAGATE ST8000NM0075 7.3T
                U12      ONLINE 0    0     0     SEAGATE ST8000NM0075 7.3T
                U13      ONLINE 0    0     0     SEAGATE ST8000NM0075 7.3T
                U14      ONLINE 0    0     0     SEAGATE ST8000NM0075 7.3T

             # zpool iostat -vc slaves
                capacity operations bandwidth
                pool       alloc free  read  write read  write slaves
                ---------- ----- ----- ----- ----- ----- ----- ---------
                tank       20.4G 7.23T 26    152   20.7M 21.6M
                mirror     20.4G 7.23T 26    152   20.7M 21.6M
                U1         -     -     0     31    1.46K 20.6M sdb sdff
                U10        -     -     0     1     3.77K 13.3K sdas sdgw
                U11        -     -     0     1     288K  13.3K sdat sdgx
                U12        -     -     0     1     78.4K 13.3K sdau sdgy
                U13        -     -     0     1     128K  13.3K sdav sdgz
                U14        -     -     0     1     63.2K 13.3K sdfk sdg

ENVIRONMENT VARIABLES

     ZFS_ABORT  Cause zpool to dump core on exit for the purposes of running ::findleaks.

     ZPOOL_IMPORT_PATH  The search path for devices or files to use with the pool. This is a
                        colon-separated list of directories in which zpool looks for device nodes
                        and files.  Similar to the -d option in zpool import.

     ZPOOL_VDEV_NAME_GUID  Cause zpool subcommands to output vdev guids by default.  This
                           behavior is identical to the zpool status -g command line option.

     ZPOOL_VDEV_NAME_FOLLOW_LINKS  Cause zpool subcommands to follow links for vdev names by
                                   default.  This behavior is identical to the zpool status -L
                                   command line option.

     ZPOOL_VDEV_NAME_PATH  Cause zpool subcommands to output full vdev path names by default.
                           This behavior is identical to the zpool status -p command line option.

     ZFS_VDEV_DEVID_OPT_OUT  Older ZFS on Linux implementations had issues when attempting to
                             display pool config VDEV names if a devid NVP value is present in
                             the pool's config.

                             For example, a pool that originated on illumos platform would have a
                             devid value in the config and zpool status would fail when listing
                             the config.  This would also be true for future Linux based pools.

                             A pool can be stripped of any devid values on import or prevented
                             from adding them on zpool create or zpool add by setting
                             ZFS_VDEV_DEVID_OPT_OUT.

     ZPOOL_SCRIPTS_AS_ROOT  Allow a privileged user to run the zpool status/iostat with the -c
                            option.  Normally, only unprivileged users are allowed to run -c.

     ZPOOL_SCRIPTS_PATH  The search path for scripts when running zpool status/iostat with the -c
                         option. This is a colon-separated list of directories and overrides the
                         default ~/.zpool.d and /etc/zfs/zpool.d search paths.

     ZPOOL_SCRIPTS_ENABLED  Allow a user to run zpool status/iostat with the -c option. If
                            ZPOOL_SCRIPTS_ENABLED is not set, it is assumed that the user is
                            allowed to run zpool status/iostat -c.

INTERFACE STABILITY

     Evolving

SEE ALSO

     zfs-events(5), zfs-module-parameters(5), zpool-features(5), zed(8), zfs(8)