zpool(8)						  System Administration Commands						  zpool(8)

NAME

       zpool - configures ZFS storage pools

SYNOPSIS

       zpool [-?]

       zpool add [-fn] pool vdev ...

       zpool attach [-f] pool device new_device

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

       zpool create [-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 replica-
       tion 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  characteris-
       tics. 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 combi-
       nations) 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 auto-
       matically 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 sin-
       gle 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  nor-
       mally. 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  compo-
       nent 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  underly-
	   ing 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  condi-
	   tions 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  transac-
       tions  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  perfor-
       mance 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 reis-
       sued 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  visibil-
       ity 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 characteris-
       tics  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. alt-
	   root  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 auto-
	   matically 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  fol-
	   lows:

	   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 behav-
	   ior 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  con-
	   figured 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 cur-
	   rently 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 open-
	       able 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 dis-
	       card 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 cur-
	   rently 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 dis-
	   plays 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 prop-
	       erties 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  proper-
	       ties.

	   -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	irretriev-
	       ably 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 per-
	       form 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 prop-
	       erties 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  proper-
	       ties.

	   -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	irretriev-
	       ably 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 per-
	       form 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 mir-
	   rored log device can be removed by specifying the top-level mirror for the log. Non-log devices that are part of a mirrored	configura-
	   tion 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  replace-
	   ment  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 prop-
	       erties 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  prop-
	       erties.

       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 dis-
	   played. 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  dis-
	   played, 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)

SunOS 5.11							    4 Jan 2010								  zpool(8)