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NAME

       zpool - configures ZFS storage pools

SYNOPSIS

       zpool [-?]

       zpool add [-fn] pool vdev ...

       zpool attach [-f] pool device new_device

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

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

       zpool destroy [-f] pool

       zpool detach pool device

       zpool export [-f] pool ...

       zpool get "all" | property[,...] pool ...

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

       zpool import [-d dir] [-D]

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

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

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

       zpool list [-H] [-o property[,...]] [pool] ...

       zpool offline [-t] pool device ...

       zpool online pool device ...

       zpool remove pool device ...

       zpool replace [-f] pool device [new_device]

       zpool scrub [-s] pool ...

       zpool set property=value pool

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

       zpool status [-xv] [pool] ...

       zpool upgrade

       zpool upgrade -v

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

DESCRIPTION

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

       All datasets within a storage pool share the same space. See zfs(1M)  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/dsk. 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/dsk"). A whole disk can be specified by  omitting  the  slice  or
           partition  designation.  For  example,  "c0t0d0" is equivalent to "/dev/dsk/c0t0d0s2".
           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 special pseudo-vdev which keeps track of available hot spares for a pool.  For  more
           information, see the "Hot Spares" section.

       log

           A  separate-intent  log  device. If more than one log device is specified, then writes
           are load-balanced between devices. Log devices can be mirrored.  However,  raidz  vdev
           types are not supported for the intent log. For more information, see the "Intent Log"
           section.

       cache

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

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

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

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

         # zpool create mypool mirror c0t0d0 c0t1d0 mirror c1t0d0 c1t1d0

   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:

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

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

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

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

       OFFLINE

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

       ONLINE

           The device is online and functioning.

       REMOVED

           The device was physically  removed  while  the  system  was  running.  Device  removal
           detection is hardware-dependent and may not be supported on all platforms.

       UNAVAIL

           The  device  could not be opened. If a pool is imported when a device was 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 c0d0 c1d0 spare c2d0 c3d0

       Spares can be shared across multiple pools, and can be added with the "zpool add"  command
       and  removed with the "zpool remove" command. Once a spare replacement is initiated, a new
       "spare" vdev is created within the configuration that will remain there until the original
       device is replaced. At this point, the hot spare becomes available again if another device
       fails.

       If a pool has a shared spare that is currently being used, the pool can  not  be  exported
       since other pools may use this shared spare, which may lead to potential data corruption.

       An  in-progress  spare  replacement  can  be  cancelled by detaching the hot spare. If the
       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() 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 c0d0 c1d0 log c2d0

       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 imported and exported as part
       of the larger pool. Mirrored log devices can be removed by specifying the top-level mirror
       for the log.

   Cache Devices
       Devices  can  be  added  to  a  storage  pool as "cache devices." These devices provide an
       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 c0d0 c1d0 cache c2d0 c3d0

       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.

   Processes
       Each imported pool has an associated process, named zpool-poolname. The  threads  in  this
       process are the pool's I/O processing threads, which handle the compression, checksumming,
       and other tasks for all I/O associated with the pool.  This  process  exists  to  provides
       visibility  into  the CPU utilization of the system's storage pools. The existence of this
       process is an unstable interface.

   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:

       alloc

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

       capacity

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

       dedupratio

           The   deduplication   ratio   specified  for  a  pool,  expressed   as  a  multiplier.
           Deduplication can be turned on by entering the command:

             # zfs set dedup=on dataset

           The default value is off.

           dedupratio is expressed as a single decimal number. For example, a dedupratio value of
           1.76  indicates  that 1.76 units of data were stored but only 1 unit of disk space was
           actually consumed.

       free

           Number of blocks within the pool that are not allocated.

       guid

           A unique identifier for the pool.

       health

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

       size

           Total size of the storage pool.

       These  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(1M) 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  properties  can be set at creation time and import time, and later changed
       with the zpool set command:

       autoexpand=on | off

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

       autoreplace=on | off

           Controls automatic device replacement. If set to "off",  device  replacement  must  be
           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".

       bootfs=pool/dataset

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

       cachefile=path | none

           Controls the location of where the pool configuration is cached. Discovering all pools
           on system startup requires a cached copy of the configuration data that is  stored  on
           the  root  file  system.  All  pools in this cache are automatically imported when the
           system boots. Some environments, such as install and clustering, need  to  cache  this
           information  in  a  different  location  so that pools are not automatically imported.
           Setting this property caches the pool configuration in a different location  that  can
           later  be  imported  with  "zpool  import  -c". Setting it to the special value "none"
           creates a temporary pool that is never cached, and the special value '' (empty string)
           uses the default location.

           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 is removed.

       delegation=on | off

           Controls whether a  non-privileged  user  is  granted  access  based  on  the  dataset
           permissions  defined on the dataset. See zfs(1M) 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 to the pool until the device connectivity is recovered and
               the errors are cleared. A pool remains in the wait state until the device issue is
               resolved. 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.

       listsnaps=on | off

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

       version=version

           The current on-disk version of the pool. This can be increased, but  never  decreased.
           The  preferred  method  of  updating pools is with the "zpool upgrade" command, though
           this  property  can  be  used  when  a  specific  version  is  needed  for   backwards
           compatibility.  This  property  can  be  any  number between 1 and the current version
           reported by "zpool upgrade -v".

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

       The  zpool  command provides subcommands to create and destroy storage pools, add capacity
       to storage  pools,  and  provide  information  about  the  storage  pools.  The  following
       subcommands are supported:

       zpool -?

           Displays a help message.

       zpool add [-fn] pool vdev ...

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

           -f

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

           -n

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

           Do not add a disk that is currently configured as a quorum device to a zpool. After  a
           disk is in the pool, that disk can then be configured as a quorum device.

       zpool attach [-f] pool device new_device

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

           -f

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

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

           Clears device errors in a pool. If no  arguments  are  specified,  all  device  errors
           within  the  pool  are cleared. If one or more devices is specified, only those errors
           associated with the specified device or devices are cleared.

           -F

               Initiates recovery mode for an unopenable pool. Attempts to discard the  last  few
               transactions  in the pool to return it to an openable state. Not all damaged pools
               can be recovered by using this option. If successful, the data from the  discarded
               transactions is irretrievably lost.

           -n

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

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

           Creates  a  new  storage  pool containing the virtual devices specified on the command
           line. The pool name must begin with  a  letter,  and  can  only  contain  alphanumeric
           characters  as  well as underscore ("_"), dash ("-"), and period ("."). The pool names
           mirror, raidz, spare, and log are reserved, as are names beginning  with  the  pattern
           c[0-9]. The vdev specification is described in the "Virtual Devices" section.

           The command verifies that each device specified is accessible and not currently in use
           by another subsystem. There are  some  uses,  such  as  being  currently  mounted,  or
           specified as the dedicated dump device, that prevents a device from ever being used by
           ZFS. Other uses, such as having a preexisting UFS file system, can be overridden  with
           the -f option.

           The  command  also checks that the replication strategy for the pool is consistent. An
           attempt to combine redundant and non-redundant storage in a single  pool,  or  to  mix
           disks  and  files,  results in an error unless -f is specified. The use of differently
           sized devices within a single raidz or mirror group is also flagged as an error unless
           -f is specified.

           Unless the -R option is specified, the default mount point is "/pool". The mount point
           must not exist or must be empty, or else the root dataset cannot be mounted. This  can
           be overridden with the -m option.

           -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.

           -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 [-o property=value] ...

               Sets the given pool properties. See the "Properties" section for a list  of  valid
               properties that can be set.

           -O file-system-property=value
           [-O file-system-property=value] ...

               Sets the given file system properties in the root file system of the pool. See the
               "Properties" section of zfs(1M) for a list of valid properties that can be set.

           -R root

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

           -m mountpoint

               Sets the mount point for the root dataset. The default mount point is  "/pool"  or
               "altroot/pool"  if altroot is specified. The mount point must be an absolute path,
               "legacy", or "none". For more information on dataset mount points, see zfs(1M).

       zpool destroy [-f] pool

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

           -f

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

       zpool detach pool device

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

       zpool export [-f] pool ...

           Exports the given pools from the system. All devices are marked as exported,  but  are
           still  considered in use by other subsystems. The devices can be moved between systems
           (even those of different endianness) and imported as long as a  sufficient  number  of
           devices are present.

           Before  exporting the pool, all datasets within the pool are unmounted. A pool can not
           be exported if it has a shared spare that is currently being used.

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

           -f

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

               This command will forcefully export the pool even if it has a shared spare that is
               currently being used. This may lead to potential data corruption.

       zpool get "all" | property[,...] pool ...

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

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

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

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

           Displays the command history of the specified  pools  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 dir | -c cachefile] [-D]

           Lists  pools  available  to  import.  If  the -d option is not specified, this command
           searches for devices in "/dev/dsk". The -d option can be specified multiple times, and
           all  directories  are  searched. If the device appears to be part of an exported pool,
           this command displays a summary of the pool with the  name  of  the  pool,  a  numeric
           identifier,  as  well  as  the  vdev  layout and current health of the device for each
           device or file. Destroyed pools, pools that were previously destroyed with the  "zpool
           destroy" command, are not listed unless the -D option is specified.

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

           -c cachefile

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

           -d dir

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

           -D

               Lists destroyed pools only.

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

           Imports  all pools found in the search directories. Identical to the previous command,
           except that all pools with a sufficient number  of  devices  available  are  imported.
           Destroyed  pools,  pools  that  were  previously  destroyed  with  the "zpool destroy"
           command, will not be imported unless the -D option is specified.

           -o mntopts

               Comma-separated list of mount options to use when  mounting  datasets  within  the
               pool. See zfs(1M) for a description of dataset properties and mount options.

           -o property=value

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

           -c cachefile

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

           -d dir

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

           -D

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

           -f

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

           -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.

           -a

               Searches for and imports all pools found.

           -R root

               Sets the "cachefile" property to "none" and the "altroot" property to "root".

           -n

               Used with the -F recovery option. Determines whether a non-importable pool can  be
               made  importable  again, but does not actually perform the pool recovery. For more
               details about pool recovery mode, see the -F option, above.

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

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

           If  a device is removed from a system without running "zpool export" first, the device
           appears as potentially active. It cannot be determined if this was a failed export, or
           whether the device is really in use from another host. To import a pool in this state,
           the -f option is required.

           -o mntopts

               Comma-separated list of mount options to use when  mounting  datasets  within  the
               pool. See zfs(1M) for a description of dataset properties and mount options.

           -o property=value

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

           -c cachefile

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

           -d dir

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

           -D

               Imports destroyed 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.

           -R root

               Sets the "cachefile" property to "none" and the "altroot" property to "root".

           -n

               Used with the -F recovery option. Determines whether a non-importable pool can  be
               made  importable  again, but does not actually perform the pool recovery. For more
               details about pool recovery mode, see the -F option, above.

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

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

           -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-wide statistics.

       zpool list [-H] [-o props[,...]] [pool] ...

           Lists  the  given  pools  along  with  a  health status and space usage. When given no
           arguments, all pools in the system are listed.

           -H

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

           -o props

               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,
               capacity, health, altroot.

       zpool offline [-t] pool device ...

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

           This command is not applicable to spares or cache devices.

           -t

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

       zpool online [-e] pool device...

           Brings the specified physical device online.

           This command is not applicable to spares or cache devices.

           -e

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

       zpool remove pool device ...

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

       zpool replace [-f] pool old_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/dsk path as the old device, even though it is actually a different disk. ZFS
           recognizes this.

           -f

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

       zpool scrub [-s] pool ...

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

           Scrubbing  and  resilvering  are  very  similar  operations.  The  difference  is that
           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 already in progress, the "zpool scrub" command terminates it and
           starts a new scrub. If a resilver is in progress, ZFS does not allow  a  scrub  to  be
           started until the resilver completes.

           -s

               Stop scrubbing.

       zpool set property=value pool

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

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

           Splits off one disk from each mirrored top-level vdev in a pool and creates a new pool
           from the split-off disks. The original pool must be made up of one or more mirrors and
           must not be in the process of resilvering.  The  split  subcommand  chooses  the  last
           device  in each mirror vdev unless overridden by a device specification on the command
           line.

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

           -R altroot

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

           -n

               Displays the configuration that would be created without  actually  splitting  the
               pool.  The  actual  pool  split could still fail due to insufficient privileges or
               device status.

           -o mntopts

               Comma-separated list of mount options to use when  mounting  datasets  within  the
               pool. See zfs(1M) for a description of dataset properties and mount options. Valid
               only in conjunction with the -R option.

           -o property=value

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

       zpool status [-xv] [pool] ...

           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.

           -x

               Only  display  status  for  pools  that  are  exhibiting  errors  or are otherwise
               unavailable.

           -v

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

       zpool upgrade

           Displays all pools formatted using a different ZFS on-disk version. Older versions can
           continue to be used, but some features may  not  be  available.  These  pools  can  be
           upgraded using "zpool upgrade -a". Pools that are formatted with a more recent version
           are also displayed, although these pools will be inaccessible on the system.

       zpool upgrade -v

           Displays ZFS versions supported by the current software. The current ZFS versions  and
           all  previous  supported  versions  are  displayed,  along  with an explanation of the
           features provided with each version.

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

           Upgrades the given pool to the latest on-disk version. Once this  is  done,  the  pool
           will no longer be accessible on systems running older versions of the software.

           -a

               Upgrades all pools.

           -V version

               Upgrade  to  the  specified  version. If the -V flag is not specified, the pool is
               upgraded to the most recent version. This option can only be used to increase  the
               version number, and only up to the most recent version supported by this software.

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 c0t0d0 c0t1d0 c0t2d0 c0t3d0 c0t4d0 c0t5d0

       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 c0t0d0 c0t1d0 mirror c0t2d0 c0t3d0

       Example 3 Creating a ZFS Storage Pool by Using Slices

       The following command creates an unmirrored pool using two disk slices.

         # zpool create tank /dev/dsk/c0t0d0s1 c0t1d0s4

       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 c1t0d0 c1t1d0

       Example 6 Listing Available ZFS Storage Pools

       The following command lists all available pools on the system.

         # zpool list
         NAME    SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
         pool    136G   109M   136G     0%  3.00x  ONLINE  -
         rpool  67.5G  12.6G  54.9G    18%  1.01x  ONLINE  -

       Example 7 Listing All Properties for a Pool

       The following command lists all the properties for a pool.

         % zpool get all pool
         NAME  PROPERTY       VALUE       SOURCE
         pool  size           136G        -
         pool  capacity       0%          -
         pool  altroot        -           default
         pool  health         ONLINE      -
         pool  guid           15697759092019394988  default
         pool  version        21          default
         pool  bootfs         -           default
         pool  delegation     on          default
         pool  autoreplace    off         default
         pool  cachefile      -           default
         pool  failmode       wait        default
         pool  listsnapshots  off         default
         pool  autoexpand     off         default
         pool  dedupratio     3.00x       -
         pool  free           136G        -
         pool  allocated      109M        -

       Example 8 Destroying a ZFS Storage Pool

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

         # zpool destroy -f tank

       Example 9 Exporting a ZFS Storage Pool

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

         # zpool export tank

       Example 10 Importing a ZFS Storage Pool

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

       The results from this command are similar to the following:

         # zpool import
           pool: tank
             id: 7678868315469843843
          state: ONLINE
         action: The pool can be imported using its name or numeric identifier.
         config:

                 tank        ONLINE
                   mirror-0  ONLINE
                     c1t2d0  ONLINE
                     c1t3d0  ONLINE

         # zpool import tank

       Example 11 Upgrading All ZFS Storage Pools to the Current Version

       The following command upgrades all ZFS  Storage  pools  to  the  current  version  of  the
       software.

         # zpool upgrade -a
         This system is currently running ZFS pool version 19.

         All pools are formatted using this version.

       Example 12 Managing Hot Spares

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

         # zpool create tank mirror c0t0d0 c0t1d0 spare c0t2d0

       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 c0t0d0 c0t3d0

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

         # zpool remove tank c0t2d0

       Example 13 Creating a ZFS Pool with Mirrored Separate Intent Logs

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

         # zpool create pool mirror c0d0 c1d0 mirror c2d0 c3d0 log mirror \
            c4d0 c5d0

       Example 14 Adding Cache Devices to a ZFS Pool

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

         # zpool add pool cache c2d0 c3d0

       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 15 Removing a Mirrored Log Device

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

       Given this configuration:

            pool: tank
           state: ONLINE
           scrub: none requested
         config:

                  NAME        STATE     READ WRITE CKSUM
                  tank        ONLINE       0     0     0
                    mirror-0  ONLINE       0     0     0
                      c6t0d0  ONLINE       0     0     0
                      c6t1d0  ONLINE       0     0     0
                    mirror-1  ONLINE       0     0     0
                      c6t2d0  ONLINE       0     0     0
                      c6t3d0  ONLINE       0     0     0
                  logs
                    mirror-2  ONLINE       0     0     0
                      c4t0d0  ONLINE       0     0     0
                      c4t1d0  ONLINE       0     0     0

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

         # zpool remove tank mirror-2

       Example 16 Recovering a Faulted ZFS Pool

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

       Recover a cached pool with the zpool clear command:

         # zpool clear -F data
         Pool data returned to its state as of Tue Sep 08 13:23:35 2009.
         Discarded approximately 29 seconds of transactions.

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

         # zpool import -F data
         Pool data returned to its state as of Tue Sep 08 13:23:35 2009.
         Discarded approximately 29 seconds of transactions.

EXIT STATUS

       The following exit values are returned:

       0

           Successful completion.

       1

           An error occurred.

       2

           Invalid command line options were specified.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       ┌─────────────────────────────┬─────────────────────────────┐
       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
       ├─────────────────────────────┼─────────────────────────────┤
       │Availability                 │SUNWzfsu                     │
       ├─────────────────────────────┼─────────────────────────────┤
       │Interface Stability          │Committed                    │
       └─────────────────────────────┴─────────────────────────────┘

SEE ALSO

       zfs(1M), attributes(5)