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3 .\" Copyright (c) 2013-2014, Xin Li <delphij@FreeBSD.org>.
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34 .Nd configures ZFS storage pools
45 .Ar pool device new_device
54 .Op Fl o Ar property Ns = Ns Ar value
56 .Op Fl O Ar file-system-property Ns = Ns Ar value
58 .Op Fl m Ar mountpoint
75 .Op Fl o Ar field Ns Op , Ns Ar ...
76 .Ar all | property Ns Op , Ns Ar ...
85 .Op Fl d Ar dir | Fl c Ar cachefile
90 .Op Fl o Ar property Ns = Ns Ar value
92 .Op Fl d Ar dir | Fl c Ar cachefile
103 .Op Fl o Ar property Ns = Ns Ar value
105 .Op Fl d Ar dir | Fl c Ar cachefile
116 .Op Fl T Cm d Ns | Ns Cm u
127 .Op Fl o Ar property Ns Op , Ns Ar ...
128 .Op Fl T Cm d Ns | Ns Cm u
131 .Op Ar inverval Op Ar count
160 .Ar property Ns = Ns Ar value pool
166 .Op Fl o Ar property Ns = Ns Ar value
172 .Op Fl T Cm d Ns | Ns Cm u
175 .Op Ar interval Op Ar count
188 storage pools. A storage pool is a collection of devices that provides physical
189 storage and data replication for
193 All datasets within a storage pool share the same space. See
195 for information on managing datasets.
196 .Ss Virtual Devices (vdevs)
200 describes a single device or a collection of devices organized according to
201 certain performance and fault characteristics. The following virtual devices
203 .Bl -tag -width "XXXXXX"
205 A block device, typically located under
208 can use individual slices or partitions, though the recommended mode of
209 operation is to use whole disks. A disk can be specified by a full path to the
212 provider name. When given a whole disk,
214 automatically labels the disk, if necessary.
216 A regular file. The use of files as a backing store is strongly discouraged. It
217 is designed primarily for experimental purposes, as the fault tolerance of a
218 file is only as good the file system of which it is a part. A file must be
219 specified by a full path.
221 A mirror of two or more devices. Data is replicated in an identical fashion
222 across all components of a mirror. A mirror with
228 bytes and can withstand
230 devices failing before data integrity is compromised.
233 .Sy raidz1 raidz2 raidz3 ) .
236 that allows for better distribution of parity and eliminates the
238 write hole (in which data and parity become inconsistent after a power loss).
239 Data and parity is striped across all disks within a
245 group can have single-, double- , or triple parity, meaning that the
247 group can sustain one, two, or three failures, respectively, without
250 type specifies a single-parity
254 type specifies a double-parity
258 type specifies a triple-parity
273 parity disks can hold approximately
278 bytes and can withstand
280 device(s) failing before data integrity is compromised. The minimum number of
283 group is one more than the number of parity disks. The
284 recommended number is between 3 and 9 to help increase performance.
287 .No pseudo- Ns No vdev
288 which keeps track of available hot spares for a pool.
289 For more information, see the
293 A separate-intent log device. If more than one log device is specified, then
294 writes are load-balanced between devices. Log devices can be mirrored. However,
297 types are not supported for the intent log. For more information,
302 A device used to cache storage pool data. A cache device cannot be configured
305 group. For more information, see the
310 Virtual devices cannot be nested, so a mirror or
312 virtual device can only
313 contain files or disks. Mirrors of mirrors (or other combinations) are not
316 A pool can have any number of virtual devices at the top of the configuration
320 Data is dynamically distributed across all top-level devices to balance data
321 among devices. As new virtual devices are added,
323 automatically places data on the newly available devices.
325 Virtual devices are specified one at a time on the command line, separated by
326 whitespace. The keywords
330 are used to distinguish where a group ends and another begins. For example, the
331 following creates two root
333 each a mirror of two disks:
334 .Bd -literal -offset 2n
335 .Li # Ic zpool create mypool mirror da0 da1 mirror da2 da3
337 .Ss Device Failure and Recovery
339 supports a rich set of mechanisms for handling device failure and data
340 corruption. All metadata and data is checksummed, and
342 automatically repairs bad data from a good copy when corruption is detected.
344 In order to take advantage of these features, a pool must make use of some form
345 of redundancy, using either mirrored or
349 supports running in a non-redundant configuration, where each root
351 is simply a disk or file, this is strongly discouraged. A single case of bit
352 corruption can render some or all of your data unavailable.
354 A pool's health status is described by one of three states: online, degraded,
355 or faulted. An online pool has all devices operating normally. A degraded pool
356 is one in which one or more devices have failed, but the data is still
357 available due to a redundant configuration. A faulted pool has corrupted
358 metadata, or one or more faulted devices, and insufficient replicas to continue
361 The health of the top-level
366 potentially impacted by the state of its associated
368 or component devices. A top-level
370 or component device is in one of the following states:
371 .Bl -tag -width "DEGRADED"
373 One or more top-level
375 is in the degraded state because one or more
376 component devices are offline. Sufficient replicas exist to continue
379 One or more component devices is in the degraded or faulted state, but
380 sufficient replicas exist to continue functioning. The underlying conditions
382 .Bl -bullet -offset 2n
384 The number of checksum errors exceeds acceptable levels and the device is
385 degraded as an indication that something may be wrong.
387 continues to use the device as necessary.
391 errors exceeds acceptable levels. The device could not be
392 marked as faulted because there are insufficient replicas to continue
396 One or more top-level
398 is in the faulted state because one or more
399 component devices are offline. Insufficient replicas exist to continue
402 One or more component devices is in the faulted state, and insufficient
403 replicas exist to continue functioning. The underlying conditions are as
405 .Bl -bullet -offset 2n
407 The device could be opened, but the contents did not match expected values.
411 errors exceeds acceptable levels and the device is faulted to
412 prevent further use of the device.
415 The device was explicitly taken offline by the
419 The device is online and functioning.
421 The device was physically removed while the system was running. Device removal
422 detection is hardware-dependent and may not be supported on all platforms.
424 The device could not be opened. If a pool is imported when a device was
425 unavailable, then the device will be identified by a unique identifier instead
426 of its path since the path was never correct in the first place.
429 If a device is removed and later reattached to the system,
431 attempts to put the device online automatically. Device attach detection is
432 hardware-dependent and might not be supported on all platforms.
435 allows devices to be associated with pools as
437 These devices are not actively used in the pool, but when an active device
438 fails, it is automatically replaced by a hot spare. To create a pool with hot
442 with any number of devices. For example,
443 .Bd -literal -offset 2n
444 .Li # Ic zpool create pool mirror da0 da1 spare da2 da3
447 Spares can be shared across multiple pools, and can be added with the
449 command and removed with the
451 command. Once a spare replacement is initiated, a new "spare"
454 within the configuration that will remain there until the original device is
455 replaced. At this point, the hot spare becomes available again if another
458 If a pool has a shared spare that is currently being used, the pool can not be
459 exported since other pools may use this shared spare, which may lead to
460 potential data corruption.
462 An in-progress spare replacement can be cancelled by detaching the hot spare.
463 If the original faulted device is detached, then the hot spare assumes its
464 place in the configuration, and is removed from the spare list of all active
467 Spares cannot replace log devices.
469 This feature requires a userland helper.
473 It must be manually enabled by adding
474 .Va zfsd_enable="YES"
484 requirements for synchronous transactions. For instance, databases often
485 require their transactions to be on stable storage devices when returning from
488 and other applications can also use
490 to ensure data stability. By default, the intent log is allocated from blocks
491 within the main pool. However, it might be possible to get better performance
492 using separate intent log devices such as
494 or a dedicated disk. For example:
495 .Bd -literal -offset 2n
496 .Li # Ic zpool create pool da0 da1 log da2
499 Multiple log devices can also be specified, and they can be mirrored. See the
501 section for an example of mirroring multiple log devices.
503 Log devices can be added, replaced, attached, detached, imported and exported
504 as part of the larger pool. Mirrored log devices can be removed by specifying
505 the top-level mirror for the log.
507 Devices can be added to a storage pool as "cache devices." These devices
508 provide an additional layer of caching between main memory and disk. For
509 read-heavy workloads, where the working set size is much larger than what can
510 be cached in main memory, using cache devices allow much more of this working
511 set to be served from low latency media. Using cache devices provides the
512 greatest performance improvement for random read-workloads of mostly static
515 To create a pool with cache devices, specify a "cache"
517 with any number of devices. For example:
518 .Bd -literal -offset 2n
519 .Li # Ic zpool create pool da0 da1 cache da2 da3
522 Cache devices cannot be mirrored or part of a
524 configuration. If a read
525 error is encountered on a cache device, that read
527 is reissued to the original storage pool device, which might be part of a
532 The content of the cache devices is considered volatile, as is the case with
535 Each pool has several properties associated with it. Some properties are
536 read-only statistics while others are configurable and change the behavior of
537 the pool. The following are read-only properties:
538 .Bl -tag -width "dedupratio"
540 Amount of storage space within the pool that has been physically allocated.
542 Percentage of pool space used. This property can also be referred to by its
543 shortened column name, "cap".
545 A text string consisting of printable ASCII characters that will be stored
546 such that it is available even if the pool becomes faulted. An administrator
547 can provide additional information about a pool using this property.
549 The deduplication ratio specified for a pool, expressed as a multiplier.
552 value of 1.76 indicates that 1.76 units of data were stored but only 1 unit of disk space was actually consumed. See
554 for a description of the deduplication feature.
556 Amount of uninitialized space within the pool or device that can be used to
557 increase the total capacity of the pool.
558 Uninitialized space consists of
559 any space on an EFI labeled vdev which has not been brought online
560 .Pq i.e. zpool online -e .
561 This space occurs when a LUN is dynamically expanded.
563 The amount of fragmentation in the pool.
565 Number of blocks within the pool that are not allocated.
567 After a file system or snapshot is destroyed, the space it was using is
568 returned to the pool asynchronously.
570 is the amount of space remaining to be reclaimed.
577 A unique identifier for the pool.
579 The current health of the pool. Health can be
588 Total size of the storage pool.
589 .It Sy unsupported@ Ns Ar feature_guid
590 Information about unsupported features that are enabled on the pool.
595 Amount of storage space used within the pool.
598 The space usage properties report actual physical space available to the
599 storage pool. The physical space can be different from the total amount of
600 space that any contained datasets can actually use. The amount of space used in
603 configuration depends on the characteristics of the data being written.
606 reserves some space for internal accounting that the
608 command takes into account, but the
610 command does not. For non-full pools of a reasonable size, these effects should
611 be invisible. For small pools, or pools that are close to being completely
612 full, these discrepancies may become more noticeable.
614 The following property can be set at creation time and import time:
617 Alternate root directory. If set, this directory is prepended to any mount
618 points within the pool. This can be used when examining an unknown pool where
619 the mount points cannot be trusted, or in an alternate boot environment, where
620 the typical paths are not valid.
622 is not a persistent property. It is valid only while the system is up.
627 though this may be overridden using an explicit setting.
630 The following property can only be set at import time:
632 .It Sy readonly Ns = Ns Cm on No | Cm off
635 pool will be imported in read-only mode with the following restrictions:
636 .Bl -bullet -offset 2n
638 Synchronous data in the intent log will not be accessible
640 Properties of the pool can not be changed
642 Datasets of this pool can only be mounted read-only
644 To write to a read-only pool, a export and import of the pool is required.
647 This property can also be referred to by its shortened column name,
651 The following properties can be set at creation time and import time, and later
656 .It Sy autoexpand Ns = Ns Cm on No | Cm off
657 Controls automatic pool expansion when the underlying LUN is grown. If set to
659 the pool will be resized according to the size of the expanded
660 device. If the device is part of a mirror or
662 then all devices within that
663 .No mirror/ Ns No raidz
664 group must be expanded before the new space is made available to
665 the pool. The default behavior is
667 This property can also be referred to by its shortened column name,
669 .It Sy autoreplace Ns = Ns Cm on No | Cm off
670 Controls automatic device replacement. If set to
672 device replacement must be initiated by the administrator by using the
676 any new device, found in the same
677 physical location as a device that previously belonged to the pool, is
678 automatically formatted and replaced. The default behavior is
680 This property can also be referred to by its shortened column name, "replace".
681 .It Sy bootfs Ns = Ns Ar pool Ns / Ns Ar dataset
682 Identifies the default bootable dataset for the root pool. This property is
683 expected to be set mainly by the installation and upgrade programs.
684 .It Sy cachefile Ns = Ns Ar path No | Cm none
685 Controls the location of where the pool configuration is cached. Discovering
686 all pools on system startup requires a cached copy of the configuration data
687 that is stored on the root file system. All pools in this cache are
688 automatically imported when the system boots. Some environments, such as
689 install and clustering, need to cache this information in a different location
690 so that pools are not automatically imported. Setting this property caches the
691 pool configuration in a different location that can later be imported with
692 .Qq Nm Cm import Fl c .
693 Setting it to the special value
695 creates a temporary pool that is never cached, and the special value
697 (empty string) uses the default location.
698 .It Sy comment Ns = Ns Ar text
699 A text string consisting of printable ASCII characters that will be stored
700 such that it is available even if the pool becomes faulted.
701 An administrator can provide additional information about a pool using this
703 .It Sy dedupditto Ns = Ns Ar number
704 Threshold for the number of block ditto copies. If the reference count for a
705 deduplicated block increases above this number, a new ditto copy of this block
706 is automatically stored. Default setting is
708 which causes no ditto copies to be created for deduplicated blocks.
709 The miniumum legal nonzero setting is 100.
710 .It Sy delegation Ns = Ns Cm on No | Cm off
711 Controls whether a non-privileged user is granted access based on the dataset
712 permissions defined on the dataset. See
714 for more information on
716 delegated administration.
717 .It Sy failmode Ns = Ns Cm wait No | Cm continue No | Cm panic
718 Controls the system behavior in the event of catastrophic pool failure. This
719 condition is typically a result of a loss of connectivity to the underlying
720 storage device(s) or a failure of all devices within the pool. The behavior of
721 such an event is determined as follows:
722 .Bl -tag -width indent
726 access until the device connectivity is recovered and the errors are cleared.
727 This is the default behavior.
733 requests but allows reads to any of the remaining healthy devices. Any write
734 requests that have yet to be committed to disk would be blocked.
736 Prints out a message to the console and generates a system crash dump.
738 .It Sy feature@ Ns Ar feature_name Ns = Ns Sy enabled
739 The value of this property is the current state of
741 The only valid value when setting this property is
745 to the enabled state.
748 for details on feature states.
749 .It Sy listsnaps Ns = Ns Cm on No | Cm off
750 Controls whether information about snapshots associated with this pool is
755 option. The default value is
757 .It Sy version Ns = Ns Ar version
758 The current on-disk version of the pool. This can be increased, but never
759 decreased. The preferred method of updating pools is with the
761 command, though this property can be used when a specific version is needed
762 for backwards compatibility.
763 Once feature flags is enabled on a pool this property will no longer have a
767 All subcommands that modify state are logged persistently to the pool in their
772 command provides subcommands to create and destroy storage pools, add capacity
773 to storage pools, and provide information about the storage pools. The following
774 subcommands are supported:
781 Displays a help message.
789 Adds the specified virtual devices to the given pool. The
791 specification is described in the
792 .Qq Sx Virtual Devices
793 section. The behavior of the
795 option, and the device checks performed are described in the
798 .Bl -tag -width indent
802 even if they appear in use or specify a conflicting replication level.
803 Not all devices can be overridden in this manner.
805 Displays the configuration that would be used without actually adding the
807 The actual pool creation can still fail due to insufficient privileges or device
810 Do not add a disk that is currently configured as a quorum device to a zpool.
811 After a disk is in the pool, that disk can then be configured as a quorum
818 .Ar pool device new_device
825 device. The existing device cannot be part of a
829 is not currently part of a mirrored configuration,
831 automatically transforms into a two-way mirror of
832 .Ar device No and Ar new_device .
835 is part of a two-way mirror, attaching
837 creates a three-way mirror, and so on. In either case,
839 begins to resilver immediately.
840 .Bl -tag -width indent
844 even if its appears to be in use. Not all devices can be overridden in this
855 Clears device errors in a pool. If no arguments are specified, all device
856 errors within the pool are cleared. If one or more devices is specified, only
857 those errors associated with the specified device or devices are cleared.
858 .Bl -tag -width indent
860 Initiates recovery mode for an unopenable pool. Attempts to discard the last
861 few transactions in the pool to return it to an openable state. Not all damaged
862 pools can be recovered by using this option. If successful, the data from the
863 discarded transactions is irretrievably lost.
865 Used in combination with the
867 flag. Check whether discarding transactions would make the pool openable, but
868 do not actually discard any transactions.
874 .Op Fl o Ar property Ns = Ns Ar value
876 .Op Fl O Ar file-system-property Ns = Ns Ar value
878 .Op Fl m Ar mountpoint
883 Creates a new storage pool containing the virtual devices specified on the
884 command line. The pool name must begin with a letter, and can only contain
885 alphanumeric characters as well as underscore ("_"), dash ("-"), and period
886 ("."). The pool names "mirror", "raidz", "spare" and "log" are reserved, as are
887 names beginning with the pattern "c[0-9]". The
889 specification is described in the
890 .Qq Sx Virtual Devices
893 The command verifies that each device specified is accessible and not currently
894 in use by another subsystem. There are some uses, such as being currently
895 mounted, or specified as the dedicated dump device, that prevents a device from
898 Other uses, such as having a preexisting
900 file system, can be overridden with the
904 The command also checks that the replication strategy for the pool is
905 consistent. An attempt to combine redundant and non-redundant storage in a
906 single pool, or to mix disks and files, results in an error unless
908 is specified. The use of differently sized devices within a single
910 or mirror group is also flagged as an error unless
916 option is specified, the default mount point is
918 The mount point must not exist or must be empty, or else the
919 root dataset cannot be mounted. This can be overridden with the
923 By default all supported features are enabled on the new pool unless the
926 .Bl -tag -width indent
930 even if they appear in use or specify a conflicting replication level.
931 Not all devices can be overridden in this manner.
933 Displays the configuration that would be used without actually creating the
934 pool. The actual pool creation can still fail due to insufficient privileges or
937 Do not enable any features on the new pool.
938 Individual features can be enabled by setting their corresponding properties
946 for details about feature properties.
948 .Fl o Ar property Ns = Ns Ar value
949 .Op Fl o Ar property Ns = Ns Ar value
952 Sets the given pool properties. See the
954 section for a list of valid properties that can be set.
957 .Ar file-system-property Ns = Ns Ar value
958 .Op Fl O Ar file-system-property Ns = Ns Ar value
961 Sets the given file system properties in the root file system of the pool. See
963 for a list of valid properties that
967 .Qq Fl o Cm cachefile=none,altroot= Ns Pa root
968 .It Fl m Ar mountpoint
969 Sets the mount point for the root dataset. The default mount point is
972 .Qq Cm altroot Ns Pa /pool
975 is specified. The mount point must be an absolute path,
979 For more information on dataset mount points, see
989 Destroys the given pool, freeing up any devices for other use. This command
990 tries to unmount any active datasets before destroying the pool.
991 .Bl -tag -width indent
993 Forces any active datasets contained within the pool to be unmounted.
1003 from a mirror. The operation is refused if there are no other valid replicas
1012 Exports the given pools from the system. All devices are marked as exported,
1013 but are still considered in use by other subsystems. The devices can be moved
1014 between systems (even those of different endianness) and imported as long as a
1015 sufficient number of devices are present.
1017 Before exporting the pool, all datasets within the pool are unmounted. A pool
1018 can not be exported if it has a shared spare that is currently being used.
1020 For pools to be portable, you must give the
1022 command whole disks, not just slices, so that
1024 can label the disks with portable
1026 labels. Otherwise, disk drivers on platforms of different endianness will not
1027 recognize the disks.
1028 .Bl -tag -width indent
1030 Forcefully unmount all datasets, using the
1034 This command will forcefully export the pool even if it has a shared spare that
1035 is currently being used. This may lead to potential data corruption.
1041 .Op Fl o Ar field Ns Op , Ns Ar ...
1042 .Ar all | property Ns Op , Ns Ar ...
1046 Retrieves the given list of properties (or all properties if
1048 is used) for the specified storage pool(s). These properties are displayed with
1049 the following fields:
1050 .Bl -column -offset indent "property"
1051 .It name Ta Name of storage pool
1052 .It property Ta Property name
1053 .It value Ta Property value
1054 .It source Ta Property source, either 'default' or 'local'.
1059 section for more information on the available pool properties.
1061 Scripted mode. Do not display headers, and separate fields by a single tab
1062 instead of arbitrary space.
1064 Display numbers in parsable (exact) values.
1066 A comma-separated list of columns to display.
1068 .Sy property Ns , Ns
1071 is the default value.
1080 Displays the command history of the specified pools or all pools if no pool is
1082 .Bl -tag -width indent
1084 Displays internally logged
1086 events in addition to user initiated events.
1088 Displays log records in long format, which in addition to standard format
1089 includes, the user name, the hostname, and the zone in which the operation was
1095 .Op Fl d Ar dir | Fl c Ar cachefile
1099 Lists pools available to import. If the
1101 option is not specified, this command searches for devices in
1105 option can be specified multiple times, and all directories are searched. If
1106 the device appears to be part of an exported pool, this command displays a
1107 summary of the pool with the name of the pool, a numeric identifier, as well as
1110 layout and current health of the device for each device or file.
1111 Destroyed pools, pools that were previously destroyed with the
1113 command, are not listed unless the
1115 option is specified.
1117 The numeric identifier is unique, and can be used instead of the pool name when
1118 multiple exported pools of the same name are available.
1119 .Bl -tag -width indent
1120 .It Fl c Ar cachefile
1121 Reads configuration from the given
1123 that was created with the
1127 is used instead of searching for devices.
1129 Searches for devices or files in
1133 option can be specified multiple times.
1135 Lists destroyed pools only.
1141 .Op Fl o Ar property Ns = Ns Ar value
1143 .Op Fl d Ar dir | Fl c Ar cachefile
1153 Imports all pools found in the search directories. Identical to the previous
1154 command, except that all pools with a sufficient number of devices available
1155 are imported. Destroyed pools, pools that were previously destroyed with the
1157 command, will not be imported unless the
1159 option is specified.
1160 .Bl -tag -width indent
1162 Comma-separated list of mount options to use when mounting datasets within the
1165 for a description of dataset properties and mount options.
1166 .It Fl o Ar property Ns = Ns Ar value
1167 Sets the specified property on the imported pool. See the
1169 section for more information on the available pool properties.
1170 .It Fl c Ar cachefile
1171 Reads configuration from the given
1173 that was created with the
1177 is used instead of searching for devices.
1179 Searches for devices or files in
1183 option can be specified multiple times. This option is incompatible with the
1187 Imports destroyed pools only. The
1189 option is also required.
1191 Forces import, even if the pool appears to be potentially active.
1193 Allows a pool to import when there is a missing log device. Recent transactions
1194 can be lost because the log device will be discarded.
1196 Import the pool without mounting any file systems.
1207 Recovery mode for a non-importable pool. Attempt to return the pool to an
1208 importable state by discarding the last few transactions. Not all damaged pools
1209 can be recovered by using this option. If successful, the data from the
1210 discarded transactions is irretrievably lost. This option is ignored if the
1211 pool is importable or already imported.
1215 recovery option. Determines whether a non-importable pool can be made
1216 importable again, but does not actually perform the pool recovery. For more
1217 details about pool recovery mode, see the
1221 Searches for and imports all pools found.
1227 .Op Fl o Ar property Ns = Ns Ar value
1229 .Op Fl d Ar dir | Fl c Ar cachefile
1240 Imports a specific pool. A pool can be identified by its name or the numeric
1243 is specified, the pool is imported using the name
1245 Otherwise, it is imported with the same name as its exported name.
1247 If a device is removed from a system without running
1249 first, the device appears as potentially active. It cannot be determined if
1250 this was a failed export, or whether the device is really in use from another
1251 host. To import a pool in this state, the
1254 .Bl -tag -width indent
1256 Comma-separated list of mount options to use when mounting datasets within the
1259 for a description of dataset properties and mount options.
1260 .It Fl o Ar property Ns = Ns Ar value
1261 Sets the specified property on the imported pool. See the
1263 section for more information on the available pool properties.
1264 .It Fl c Ar cachefile
1265 Reads configuration from the given
1267 that was created with the
1271 is used instead of searching for devices.
1273 Searches for devices or files in
1277 option can be specified multiple times. This option is incompatible with the
1281 Imports destroyed pools only. The
1283 option is also required.
1285 Forces import, even if the pool appears to be potentially active.
1287 Allows a pool to import when there is a missing log device. Recent transactions
1288 can be lost because the log device will be discarded.
1290 Import the pool without mounting any file systems.
1293 .Qq Fl o Cm cachefile=none,altroot= Ns Pa root
1295 Recovery mode for a non-importable pool. Attempt to return the pool to an
1296 importable state by discarding the last few transactions. Not all damaged pools
1297 can be recovered by using this option. If successful, the data from the
1298 discarded transactions is irretrievably lost. This option is ignored if the
1299 pool is importable or already imported.
1303 recovery option. Determines whether a non-importable pool can be made
1304 importable again, but does not actually perform the pool recovery. For more
1305 details about pool recovery mode, see the
1312 .Op Fl T Cm d Ns | Ns Cm u
1316 .Op Ar interval Op Ar count
1321 statistics for the given pools. When given an interval, the statistics are
1328 are specified, statistics for every pool in the system is shown. If
1330 is specified, the command exits after
1332 reports are printed.
1333 .Bl -tag -width indent
1334 .It Fl T Cm d Ns | Ns Cm u
1339 for standard date format. See
1344 .Pq equals Qq Ic date +%s .
1346 Verbose statistics. Reports usage statistics for individual
1348 within the pool, in addition to the pool-wide statistics.
1359 label information from the specified
1363 must not be part of an active pool configuration.
1364 .Bl -tag -width indent
1366 Treat exported or foreign devices as inactive.
1372 .Op Fl o Ar property Ns Op , Ns Ar ...
1373 .Op Fl T Cm d Ns | Ns Cm u
1376 .Op Ar inverval Op Ar count
1379 Lists the given pools along with a health status and space usage. If no
1381 are specified, all pools in the system are listed.
1383 When given an interval, the output is printed every
1389 is specified, the command exits after
1391 reports are printed.
1392 .Bl -tag -width indent
1393 .It Fl T Cm d Ns | Ns Cm u
1398 for standard date format. See
1403 .Pq equals Qq Ic date +%s .
1405 Scripted mode. Do not display headers, and separate fields by a single tab
1406 instead of arbitrary space.
1408 Display numbers in parsable (exact) values.
1410 Verbose statistics. Reports usage statistics for individual
1413 the pool, in addition to the pool-wide statistics.
1414 .It Fl o Ar property Ns Op , Ns Ar ...
1415 Comma-separated list of properties to display. See the
1417 section for a list of valid properties. The default list is
1427 .It Fl T Cm d Ns | Ns Cm u
1432 for standard date format. See
1437 .Pq equals Qq Ic date +%s .
1446 Takes the specified physical device offline. While the
1448 is offline, no attempt is made to read or write to the device.
1449 .Bl -tag -width indent
1451 Temporary. Upon reboot, the specified physical device reverts to its previous
1461 Brings the specified physical device online.
1463 This command is not applicable to spares or cache devices.
1464 .Bl -tag -width indent
1466 Expand the device to use all available space. If the device is part of a mirror
1469 then all devices must be expanded before the new space will become
1470 available to the pool.
1478 Generates a new unique identifier for the pool. You must ensure that all
1479 devices in this pool are online and healthy before performing this action.
1486 Removes the specified device from the pool. This command currently only
1487 supports removing hot spares, cache, and log devices. A mirrored log device can
1488 be removed by specifying the top-level mirror for the log. Non-log devices that
1489 are part of a mirrored configuration can be removed using the
1491 command. Non-redundant and
1493 devices cannot be removed from a pool.
1500 Reopen all the vdevs associated with the pool.
1513 This is equivalent to attaching
1515 waiting for it to resilver, and then detaching
1520 must be greater than or equal to the minimum size
1521 of all the devices in a mirror or
1526 is required if the pool is not redundant. If
1528 is not specified, it defaults to
1530 This form of replacement is useful after an existing disk has failed and has
1531 been physically replaced. In this case, the new disk may have the same
1533 path as the old device, even though it is actually a different disk.
1536 .Bl -tag -width indent
1540 even if its appears to be in use. Not all devices can be overridden in this
1550 Begins a scrub. The scrub examines all data in the specified pools to verify
1551 that it checksums correctly. For replicated (mirror or
1555 automatically repairs any damage discovered during the scrub. The
1557 command reports the progress of the scrub and summarizes the results of the
1558 scrub upon completion.
1560 Scrubbing and resilvering are very similar operations. The difference is that
1561 resilvering only examines data that
1563 knows to be out of date (for example, when attaching a new device to a mirror
1564 or replacing an existing device), whereas scrubbing examines all data to
1565 discover silent errors due to hardware faults or disk failure.
1567 Because scrubbing and resilvering are
1568 .Tn I/O Ns -intensive
1571 only allows one at a time. If a scrub is already in progress, the
1573 command returns an error. To start a new scrub, you have to stop the old scrub
1575 .Qq Nm Cm scrub Fl s
1576 command first. If a resilver is in progress,
1578 does not allow a scrub to be started until the resilver completes.
1579 .Bl -tag -width indent
1586 .Ar property Ns = Ns Ar value pool
1589 Sets the given property on the specified pool. See the
1591 section for more information on what properties can be set and acceptable
1599 .Op Fl o Ar property Ns = Ns Ar value
1604 Splits off one disk from each mirrored top-level
1606 in a pool and creates a new pool from the split-off disks. The original pool
1607 must be made up of one or more mirrors and must not be in the process of
1610 subcommand chooses the last device in each mirror
1612 unless overridden by a device specification on the command line.
1618 includes the specified device(s) in a new pool and, should any devices remain
1619 unspecified, assigns the last device in each mirror
1621 to that pool, as it does normally. If you are uncertain about the outcome of a
1625 ("dry-run") option to ensure your command will have the effect you intend.
1626 .Bl -tag -width indent
1628 Automatically import the newly created pool after splitting, using the
1631 parameter for the new pool's alternate root. See the
1637 Displays the configuration that would be created without actually splitting the
1638 pool. The actual pool split could still fail due to insufficient privileges or
1641 Comma-separated list of mount options to use when mounting datasets within the
1644 for a description of dataset properties and mount options. Valid only in
1645 conjunction with the
1648 .It Fl o Ar property Ns = Ns Ar value
1649 Sets the specified property on the new pool. See the
1651 section, above, for more information on the available pool properties.
1657 .Op Fl T Cm d Ns | Ns Cm u
1660 .Op Ar interval Op Ar count
1663 Displays the detailed health status for the given pools. If no
1665 is specified, then the status of each pool in the system is displayed. For more
1666 information on pool and device health, see the
1667 .Qq Sx Device Failure and Recovery
1670 When given an interval, the output is printed every
1676 is specified, the command exits after
1678 reports are printed.
1680 If a scrub or resilver is in progress, this command reports the percentage
1681 done and the estimated time to completion. Both of these are only approximate,
1682 because the amount of data in the pool and the other workloads on the system
1684 .Bl -tag -width indent
1686 Only display status for pools that are exhibiting errors or are otherwise
1688 Warnings about pools not using the latest on-disk format, having non-native
1689 block size or disabled features will not be included.
1691 Displays verbose data error information, printing out a complete list of all
1692 data errors since the last complete pool scrub.
1693 .It Fl T Cm d Ns | Ns Cm u
1698 for standard date format. See
1703 .Pq equals Qq Ic date +%s .
1711 Displays pools which do not have all supported features enabled and pools
1712 formatted using a legacy
1715 These pools can continue to be used, but some features may not be available.
1718 to enable all features on all pools.
1719 .Bl -tag -width indent
1723 versions supported by the current software.
1725 .Xr zpool-features 7
1726 for a description of feature flags features supported by the current software.
1735 Enables all supported features on the given pool.
1736 Once this is done, the pool will no longer be accessible on systems that do
1737 not support feature flags.
1739 .Xr zpool-features 7
1740 for details on compatibility with systems that support feature flags, but do
1741 not support all features enabled on the pool.
1742 .Bl -tag -width indent
1744 Enables all supported features on all pools.
1746 Upgrade to the specified legacy version. If the
1748 flag is specified, no features will be enabled on the pool.
1749 This option can only be used to increase version number up to the last
1750 supported legacy version number.
1754 The following exit values are returned:
1755 .Bl -tag -offset 2n -width 2n
1757 Successful completion.
1761 Invalid command line options were specified.
1765 .It Sy Example 1 No Creating a RAID-Z Storage Pool
1767 The following command creates a pool with a single
1771 that consists of six disks.
1772 .Bd -literal -offset 2n
1773 .Li # Ic zpool create tank raidz da0 da1 da2 da3 da4 da5
1775 .It Sy Example 2 No Creating a Mirrored Storage Pool
1777 The following command creates a pool with two mirrors, where each mirror
1779 .Bd -literal -offset 2n
1780 .Li # Ic zpool create tank mirror da0 da1 mirror da2 da3
1782 .It Sy Example 3 No Creating a Tn ZFS No Storage Pool by Using Partitions
1784 The following command creates an unmirrored pool using two GPT partitions.
1785 .Bd -literal -offset 2n
1786 .Li # Ic zpool create tank da0p3 da1p3
1788 .It Sy Example 4 No Creating a Tn ZFS No Storage Pool by Using Files
1790 The following command creates an unmirrored pool using files. While not
1791 recommended, a pool based on files can be useful for experimental purposes.
1792 .Bd -literal -offset 2n
1793 .Li # Ic zpool create tank /path/to/file/a /path/to/file/b
1795 .It Sy Example 5 No Adding a Mirror to a Tn ZFS No Storage Pool
1797 The following command adds two mirrored disks to the pool
1799 assuming the pool is already made up of two-way mirrors. The additional space
1800 is immediately available to any datasets within the pool.
1801 .Bd -literal -offset 2n
1802 .Li # Ic zpool add tank mirror da2 da3
1804 .It Sy Example 6 No Listing Available Tn ZFS No Storage Pools
1806 The following command lists all available pools on the system.
1807 .Bd -literal -offset 2n
1809 NAME SIZE ALLOC FREE FRAG EXPANDSZ CAP DEDUP HEALTH ALTROOT
1810 pool 2.70T 473G 2.24T 33% - 17% 1.00x ONLINE -
1811 test 1.98G 89.5K 1.98G 48% - 0% 1.00x ONLINE -
1813 .It Sy Example 7 No Listing All Properties for a Pool
1815 The following command lists all the properties for a pool.
1816 .Bd -literal -offset 2n
1817 .Li # Ic zpool get all pool
1820 pool altroot - default
1821 pool health ONLINE -
1822 pool guid 2501120270416322443 default
1823 pool version 28 default
1824 pool bootfs pool/root local
1825 pool delegation on default
1826 pool autoreplace off default
1827 pool cachefile - default
1828 pool failmode wait default
1829 pool listsnapshots off default
1830 pool autoexpand off default
1831 pool dedupditto 0 default
1832 pool dedupratio 1.00x -
1834 pool allocated 473G -
1837 .It Sy Example 8 No Destroying a Tn ZFS No Storage Pool
1839 The following command destroys the pool
1841 and any datasets contained within.
1842 .Bd -literal -offset 2n
1843 .Li # Ic zpool destroy -f tank
1845 .It Sy Example 9 No Exporting a Tn ZFS No Storage Pool
1847 The following command exports the devices in pool
1849 so that they can be relocated or later imported.
1850 .Bd -literal -offset 2n
1851 .Li # Ic zpool export tank
1853 .It Sy Example 10 No Importing a Tn ZFS No Storage Pool
1855 The following command displays available pools, and then imports the pool
1857 for use on the system.
1859 The results from this command are similar to the following:
1860 .Bd -literal -offset 2n
1861 .Li # Ic zpool import
1864 id: 15451357997522795478
1866 action: The pool can be imported using its name or numeric identifier.
1878 Storage Pools to the Current Version
1881 The following command upgrades all
1883 Storage pools to the current version of
1885 .Bd -literal -offset 2n
1886 .Li # Ic zpool upgrade -a
1887 This system is currently running ZFS pool version 28.
1889 .It Sy Example 12 No Managing Hot Spares
1891 The following command creates a new pool with an available hot spare:
1892 .Bd -literal -offset 2n
1893 .Li # Ic zpool create tank mirror da0 da1 spare da2
1896 If one of the disks were to fail, the pool would be reduced to the degraded
1897 state. The failed device can be replaced using the following command:
1898 .Bd -literal -offset 2n
1899 .Li # Ic zpool replace tank da0 da2
1902 Once the data has been resilvered, the spare is automatically removed and is
1903 made available should another device fails. The hot spare can be permanently
1904 removed from the pool using the following command:
1905 .Bd -literal -offset 2n
1906 .Li # Ic zpool remove tank da2
1912 Pool with Mirrored Separate Intent Logs
1915 The following command creates a
1917 storage pool consisting of two, two-way
1918 mirrors and mirrored log devices:
1919 .Bd -literal -offset 2n
1920 .Li # Ic zpool create pool mirror da0 da1 mirror da2 da3 log mirror da4 da5
1922 .It Sy Example 14 No Adding Cache Devices to a Tn ZFS No Pool
1924 The following command adds two disks for use as cache devices to a
1927 .Bd -literal -offset 2n
1928 .Li # Ic zpool add pool cache da2 da3
1931 Once added, the cache devices gradually fill with content from main memory.
1932 Depending on the size of your cache devices, it could take over an hour for
1933 them to fill. Capacity and reads can be monitored using the
1935 subcommand as follows:
1936 .Bd -literal -offset 2n
1937 .Li # Ic zpool iostat -v pool 5
1941 Displaying expanded space on a device
1944 The following command dipslays the detailed information for the
1947 This pool is comprised of a single
1949 vdev where one of its
1950 devices increased its capacity by 10GB.
1951 In this example, the pool will not
1952 be able to utilized this extra capacity until all the devices under the
1954 vdev have been expanded.
1955 .Bd -literal -offset 2n
1956 .Li # Ic zpool list -v data
1957 NAME SIZE ALLOC FREE FRAG EXPANDSZ CAP DEDUP HEALTH ALTROOT
1958 data 23.9G 14.6G 9.30G 48% - 61% 1.00x ONLINE -
1959 raidz1 23.9G 14.6G 9.30G 48% -
1966 Removing a Mirrored Log Device
1969 The following command removes the mirrored log device
1972 Given this configuration:
1973 .Bd -literal -offset 2n
1976 scrub: none requested
1979 NAME STATE READ WRITE CKSUM
1981 mirror-0 ONLINE 0 0 0
1984 mirror-1 ONLINE 0 0 0
1988 mirror-2 ONLINE 0 0 0
1993 The command to remove the mirrored log
1996 .Bd -literal -offset 2n
1997 .Li # Ic zpool remove tank mirror-2
2001 Recovering a Faulted
2006 If a pool is faulted but recoverable, a message indicating this state is
2009 if the pool was cached (see the
2011 argument above), or as part of the error output from a failed
2015 Recover a cached pool with the
2018 .Bd -literal -offset 2n
2019 .Li # Ic zpool clear -F data
2020 Pool data returned to its state as of Tue Sep 08 13:23:35 2009.
2021 Discarded approximately 29 seconds of transactions.
2024 If the pool configuration was not cached, use
2026 with the recovery mode flag:
2027 .Bd -literal -offset 2n
2028 .Li # Ic zpool import -F data
2029 Pool data returned to its state as of Tue Sep 08 13:23:35 2009.
2030 Discarded approximately 29 seconds of transactions.
2034 .Xr zpool-features 7 ,
2038 This manual page is a
2040 reimplementation of the
2044 modified and customized for
2046 and licensed under the Common Development and Distribution License
2051 implementation of this manual page was initially written by
2052 .An Martin Matuska Aq mm@FreeBSD.org .