ZPOOL(8) | System Manager's Manual | ZPOOL(8) |
zpool
—
zpool |
[-? ] |
zpool |
add [-fn ]
pool vdev ... |
zpool |
attach [-f ]
pool device new_device |
zpool |
clear [-F
[-n ]] pool
[device] |
zpool |
create [-fnd ]
[-o
property=value]
... [-O
file-system-property=value]
... [-m
mountpoint] [-R
root] pool vdev ... |
zpool |
destroy [-f ]
pool |
zpool |
detach pool device |
zpool |
export [-f ]
pool ... |
zpool |
get [-Hp ]
[-o
field[,...]]
all |
property[,...]
pool ... |
zpool |
history [-il ]
[pool] ... |
zpool |
import [-d
dir | -c
cachefile] [-D ] |
zpool |
import [-o
mntopts] [-o
property=value]
... [-d
dir | -c
cachefile] [-D ]
[-f ] [-m ]
[-N ] [-R
root] [-F
[-n ]] -a |
zpool |
import [-o
mntopts] [-o
property=value]
... [-d
dir | -c
cachefile] [-D ]
[-f ] [-m ]
[-N ] [-R
root] [-F
[-n ]] pool |
id [newpool] |
zpool |
iostat [-T
d |u ]
[-v ] [pool]
... |
zpool |
labelclear [-f ]
device |
zpool |
list [-Hpv ]
[-o
property[,...]]
[-T
d |u ]
[pool] ...
[inverval [count]] |
zpool |
offline [-t ]
pool device ... |
zpool |
online [-e ]
pool device ... |
zpool |
reguid pool |
zpool |
remove pool device
... |
zpool |
reopen pool |
zpool |
replace [-f ]
pool device [new_device] |
zpool |
scrub [-s ]
pool ... |
zpool |
set
property=value pool |
zpool |
split [-n ]
[-R altroot]
[-o mntopts]
[-o
property=value]
pool newpool [device ...] |
zpool |
status [-vx ]
[-T
d |u ]
[pool] ...
[interval [count]] |
zpool |
upgrade [-v ] |
zpool |
upgrade [-V
version] -a |
pool ... |
zpool
command configures ZFS storage pools. A
storage pool is a collection of devices that provides physical storage and
data replication for ZFS datasets.
All datasets within a storage pool share the same space. See zfs(8) for information on managing datasets.
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.
Virtual devices cannot be nested, so a mirror or raidz virtual device can only contain files or disks. Mirrors of mirrors (or other combinations) are not allowed.
A pool can have any number of virtual devices at the top of the configuration (known as “root” vdevs). Data is dynamically distributed across all top-level devices to balance data among devices. As new virtual devices are added, ZFS automatically places data on the newly available devices.
Virtual devices are specified one at a time on the command line, separated by whitespace. The keywords “mirror” and “raidz” are used to distinguish where a group ends and another begins. For example, the following creates two root vdevs, each a mirror of two disks:
#
zpool create mypool mirror da0 da1 mirror da2 da3
In order to take advantage of these features, a pool must make use of some form of redundancy, using either mirrored or raidz groups. While ZFS supports running in a non-redundant configuration, where each root vdev is simply a disk or file, this is strongly discouraged. A single case of bit corruption can render some or all of your data unavailable.
A pool's health status is described by one of three states: online, degraded, or faulted. An online pool has all devices operating normally. A degraded pool is one in which one or more devices have failed, but the data is still available due to a redundant configuration. A faulted pool has corrupted metadata, or one or more faulted devices, and insufficient replicas to continue functioning.
The health of the top-level vdev, such as mirror or raidz device, is potentially impacted by the state of its associated vdevs, or component devices. A top-level vdev or component device is in one of the following states:
One or more component devices is in the degraded or faulted state, but sufficient replicas exist to continue functioning. The underlying conditions are as follows:
One or more component devices is in the faulted state, and insufficient replicas exist to continue functioning. The underlying conditions are as follows:
zpool
offline
” command.If a device is removed and later reattached to the system, ZFS attempts to put the device online automatically. Device attach detection is hardware-dependent and might not be supported on all platforms.
#
zpool create pool mirror da0 da1 spare da2 da3
Spares can be shared across multiple pools, and can be added with
the “zpool
add
” command and removed with the
“zpool
remove
”
command. Once a spare replacement is initiated, a new "spare"
vdev is created within the configuration that will
remain there until the original device is replaced. At this point, the hot
spare becomes available again if another device fails.
If a pool has a shared spare that is currently being used, the pool can not be exported since other pools may use this shared spare, which may lead to potential data corruption.
An in-progress spare replacement can be cancelled by detaching the hot spare. If the 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.
This feature requires a userland helper.
#
zpool create pool da0 da1 log da2
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, imported and exported as part of the larger pool. Mirrored log devices can be removed by specifying the top-level mirror for the log.
To create a pool with cache devices, specify a "cache" vdev with any number of devices. For example:
#
zpool create pool da0 da1 cache da2 da3
Cache devices cannot be mirrored or part of a raidz configuration. If a read error is encountered on a cache device, that read I/O is reissued to the original storage pool device, which might be part of a mirrored or raidz configuration.
The content of the cache devices is considered volatile, as is the case with other system caches.
The space usage properties report actual physical space available to the storage pool. The physical space can be different from the total amount of space that any contained datasets can actually use. The amount of space used in a raidz configuration depends on the characteristics of the data being written. In addition, ZFS reserves some space for internal accounting that the zfs(8) command takes into account, but the zpool(8) command does not. For non-full pools of a reasonable size, these effects should be invisible. For small pools, or pools that are close to being completely full, these discrepancies may become more noticeable.
The following property can be set at creation time and import time:
cachefile=none
, though this may be
overridden using an explicit setting.The following property can only be set at import time:
on
|
off
on
, pool will be imported in read-only
mode with the following restrictions:
This property can also be referred to by its shortened column name, rdonly.
The following properties can be set at creation time and import
time, and later changed with the zpool set
command:
on
|
off
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.on
|
off
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".none
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.0
which causes no ditto copies to be created for
deduplicated blocks. The miniumum legal nonzero setting is 100.on
|
off
wait
|
continue
|
panic
on
|
off
zfs
list
” is run without the
-t
option. The default value is
off
.zpool
upgrade
” command, though this property can
be used when a specific version is needed for backwards compatibility.
Once feature flags is enabled on a pool this property will no longer have
a value.The zpool
command provides subcommands to
create and destroy storage pools, add capacity to storage pools, and provide
information about the storage pools. The following subcommands are
supported:
zpool
[-?
]Displays a help message.
zpool
add
[-fn
] pool vdev ...Adds the specified virtual devices to the given pool. The
vdev specification is described in the
“Virtual
Devices” section. The behavior of the
-f
option, and the device checks performed are
described in the “zpool
create
” subcommand.
-f
-n
Do not add a disk that is currently configured as a quorum device to a zpool. After a disk is in the pool, that disk can then be configured as a quorum device.
zpool
attach
[-f
] pool device
new_deviceAttaches new_device to an existing zpool device. The existing device cannot be part of a raidz configuration. If device is not currently part of a mirrored configuration, device automatically transforms into a two-way mirror of device and new_device. If device is part of a two-way mirror, attaching new_device creates a three-way mirror, and so on. In either case, new_device begins to resilver immediately.
-f
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
-n
-F
flag. Check
whether discarding transactions would make the pool openable, but do
not actually discard any transactions.zpool
create
[-fnd
] [-o
property=value]
... [-O
file-system-property=value]
... [-m
mountpoint] [-R
root] pool vdev ...Creates a new storage pool containing the virtual devices specified on the command line. The pool name must begin with a letter, and can only contain alphanumeric characters as well as underscore ("_"), dash ("-"), and period ("."). The pool names "mirror", "raidz", "spare" and "log" are reserved, as are names beginning with the pattern "c[0-9]". The vdev specification is described in the “Virtual Devices” section.
The command verifies that each device specified is accessible
and not currently in use by another subsystem. There are some uses, such
as being currently mounted, or specified as the dedicated dump device,
that prevents a device from ever being used by ZFS Other uses, such as
having a preexisting UFS file system, can be
overridden with the -f
option.
The command also checks that the replication strategy for the
pool is consistent. An attempt to combine redundant and non-redundant
storage in a single pool, or to mix disks and files, results in an error
unless -f
is specified. The use of differently
sized devices within a single raidz or mirror
group is also flagged as an error unless -f
is
specified.
Unless the -R
option is specified, the
default mount point is “/pool”.
The mount point must not exist or must be empty, or else the root
dataset cannot be mounted. This can be overridden with the
-m
option.
By default all supported features are enabled on the new pool
unless the -d
option is specified.
-f
-n
-d
-o
option.
See
zpool-features(7)
for details about feature properties.-o
property=value
[-o
property=value]
...-O
file-system-property=value
[-O
file-system-property=value]
...-R
root-o
cachefile=none,altroot=
root”-m
mountpointaltroot
/pool”
if altroot is specified. The mount point must be an
absolute path, “legacy
”, or
“none
”. For more information on
dataset mount points, see
zfs(8).zpool
destroy
[-f
] poolDestroys the given pool, freeing up any devices for other use. This command tries to unmount any active datasets before destroying the pool.
-f
zpool
detach
pool deviceDetaches device from a mirror. The operation is refused if there are no other valid replicas of the data.
zpool
export
[-f
] pool ...Exports the given pools from the system. All devices are marked as exported, but are still considered in use by other subsystems. The devices can be moved between systems (even those of different endianness) and imported as long as a sufficient number of devices are present.
Before exporting the pool, all datasets within the pool are unmounted. A pool can not be exported if it has a shared spare that is currently being used.
For pools to be portable, you must give the
zpool
command whole disks, not just slices, so
that ZFS can label the disks with portable EFI labels.
Otherwise, disk drivers on platforms of different endianness will not
recognize the disks.
-f
unmount
-f
” command.
This command will forcefully export the pool even if it has a shared spare that is currently being used. This may lead to potential data corruption.
zpool
get
[-Hp
] [-o
field[,...]]
all |
property[,...]
pool ...Retrieves the given list of properties (or all properties if
“all
” is used) for the specified
storage pool(s). These properties are displayed with the following
fields:
name | Name of storage pool |
property | Property name |
value | Property value |
source | Property source, either 'default' or 'local'. |
See the “Properties” section for more information on the available pool properties.
-H
-p
-o
fieldzpool
history
[-il
] [pool]
...Displays the command history of the specified pools or all pools if no pool is specified.
zpool
import
[-d
dir |
-c
cachefile]
[-D
]Lists pools available to import. If the
-d
option is not specified, this command
searches for devices in “/dev”.
The -d
option can be specified multiple times,
and all directories are searched. If the device appears to be part of an
exported pool, this command displays a summary of the pool with the name
of the pool, a numeric identifier, as well as the
vdev layout and current health of the device for
each device or file. Destroyed pools, pools that were previously
destroyed with the “zpool
destroy
” command, are not listed unless
the -D
option is specified.
The numeric identifier is unique, and can be used instead of the pool name when multiple exported pools of the same name are available.
zpool
import
[-o
mntopts]
[-o
property=value]
... [-d
dir | -c
cachefile] [-D
]
[-f
] [-m
]
[-N
] [-R
root] [-F
[-n
]] -a
Imports all pools found in the search directories. Identical
to the previous command, except that all pools with a sufficient number
of devices available are imported. Destroyed pools, pools that were
previously destroyed with the “zpool
destroy
” command, will not be imported
unless the -D
option is specified.
-o
mntopts-o
property=value-c
cachefile-d
dir-d
option can be specified multiple times.
This option is incompatible with the -c
option.-D
-f
option is
also required.-f
-m
-N
-R
rootnone
” and the
“altroot” property to
“root”-F
-n
-F
recovery option. Determines
whether a non-importable pool can be made importable again, but does
not actually perform the pool recovery. For more details about pool
recovery mode, see the -F
option, above.-a
zpool
import
[-o
mntopts]
[-o
property=value]
... [-d
dir | -c
cachefile] [-D
]
[-f
] [-m
]
[-N
] [-R
root] [-F
[-n
]] pool |
id [newpool]Imports a specific pool. A pool can be identified by its name or the numeric identifier. If newpool is specified, the pool is imported using the name newpool. Otherwise, it is imported with the same name as its exported name.
If a device is removed from a system without running
“zpool
export
” first, the device appears as
potentially active. It cannot be determined if this was a failed export,
or whether the device is really in use from another host. To import a
pool in this state, the -f
option is
required.
-o
mntopts-o
property=value-c
cachefile-d
dir-d
option can be specified multiple times.
This option is incompatible with the -c
option.-D
-f
option is
also required.-f
-m
-N
-R
root-o
cachefile=none,altroot=
root”-F
-n
-F
recovery option. Determines
whether a non-importable pool can be made importable again, but does
not actually perform the pool recovery. For more details about pool
recovery mode, see the -F
option, above.zpool
iostat
[-T
d
|u
]
[-v
] [pool]
... [interval
[count]]Displays I/O statistics for the given pools. When given an interval, the statistics are printed every interval seconds until Ctrl-C is pressed. If no pools are specified, statistics for every pool in the system is shown. If count is specified, the command exits after count reports are printed.
zpool
labelclear
[-f
] deviceRemoves ZFS label information from the specified device. The device must not be part of an active pool configuration.
-f
zpool
list
[-Hpv
] [-o
property[,...]]
[-T
d
|u
]
[pool] ...
[inverval [count]]Lists the given pools along with a health status and space usage. If no pools are specified, all pools in the system are listed.
When given an interval, the output is printed every interval seconds until Ctrl-C is pressed. If count is specified, the command exits after count reports are printed.
-T
d
|u
Use modifier d
for standard date
format. See date(1). Use
modifier u
for unixtime (equals
“date +%s
”).
-H
-p
-v
-o
property[,...]-T
d
|u
Use modifier d
for standard date
format. See date(1). Use
modifier u
for unixtime (equals
“date +%s
”).
zpool
offline
[-t
] pool device ...Takes the specified physical device offline. While the device is offline, no attempt is made to read or write to the device.
-t
zpool
online
[-e
] pool device ...Brings the specified physical device online.
This command is not applicable to spares or cache devices.
-e
zpool
reguid
poolGenerates a new unique identifier for the pool. You must ensure that all devices in this pool are online and healthy before performing this action.
zpool
remove
pool device ...Removes the specified device from the pool. This command
currently only supports removing hot spares, cache, and log devices. A
mirrored log device can be removed by specifying the top-level mirror
for the log. Non-log devices that are part of a mirrored configuration
can be removed using the “zpool
detach
” command. Non-redundant and
raidz devices cannot be removed from a pool.
zpool
reopen
poolReopen all the vdevs associated with the pool.
zpool
replace
[-f
] pool device
[new_device]Replaces old_device with new_device. This is equivalent to attaching new_device, waiting for it to resilver, and then detaching old_device.
The size of new_device must be greater than or equal to the minimum size of all the devices in a mirror or raidz configuration.
new_device is required if the pool is not redundant. If new_device is not specified, it defaults to old_device. This form of replacement is useful after an existing disk has failed and has been physically replaced. In this case, the new disk may have the same /dev path as the old device, even though it is actually a different disk. ZFS recognizes this.
-f
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 returns an error. To start
a new scrub, you have to stop the old scrub with the
“zpool
scrub
-s
” command first. If a resilver is in
progress, ZFS does not allow a scrub to be started until the resilver
completes.
-s
zpool
set
property=value poolSets the given property on the specified pool. See the “Properties” section for more information on what properties can be set and acceptable values.
zpool
split
[-n
] [-R
altroot] [-o
mntopts] [-o
property=value]
pool newpool [device ...]Splits off one disk from each mirrored top-level
vdev in a pool and creates a new pool from the
split-off disks. The original pool must be made up of one or more
mirrors and must not be in the process of resilvering. The
split
subcommand chooses the last device in each
mirror vdev unless overridden by a device
specification on the command line.
When using a device argument,
split
includes the specified device(s) in a new
pool and, should any devices remain unspecified, assigns the last device
in each mirror vdev to that pool, as it does
normally. If you are uncertain about the outcome of a
split
command, use the
-n
("dry-run") option to ensure your
command will have the effect you intend.
-R
altroot-n
-o
mntopts-R
option.-o
property=valuezpool
status
[-vx
] [-T
d
|u
]
[pool] ...
[interval [count]]Displays the detailed health status for the given pools. If no pool is specified, then the status of each pool in the system is displayed. For more information on pool and device health, see the “Device Failure and Recovery” section.
When given an interval, the output is printed every interval seconds until Ctrl-C is pressed. If count is specified, the command exits after count reports are printed.
If a scrub or resilver is in progress, this command reports the percentage done and the estimated time to completion. Both of these are only approximate, because the amount of data in the pool and the other workloads on the system can change.
-x
-v
-T
d
|u
Use modifier d
for standard date
format. See date(1). Use
modifier u
for unixtime (equals
“date +%s
”).
zpool
upgrade
[-v
]Displays pools which do not have all supported features
enabled and pools formatted using a legacy ZFS version number. These
pools can continue to be used, but some features may not be available.
Use zpool
upgrade
-a
to enable all features on all pools.
-v
zpool
upgrade
[-V
version]
-a
| pool ...Enables all supported features on the given pool. Once this is done, the pool will no longer be accessible on systems that do not support feature flags. See zpool-features(7) for details on compatibility with systems that support feature flags, but do not support all features enabled on the pool.
The following command creates a pool with a single raidz root vdev that consists of six disks.
#
zpool create tank raidz da0 da1 da2 da3 da4 da5
The following command creates a pool with two mirrors, where each mirror contains two disks.
#
zpool create tank mirror da0 da1 mirror da2 da3
The following command creates an unmirrored pool using two GPT partitions.
#
zpool create tank da0p3 da1p3
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
The following command adds two mirrored disks to the pool tank, assuming the pool is already made up of two-way mirrors. The additional space is immediately available to any datasets within the pool.
#
zpool add tank mirror da2 da3
The following command lists all available pools on the system.
#
zpool list
NAME SIZE ALLOC FREE FRAG EXPANDSZ CAP DEDUP HEALTH ALTROOT pool 2.70T 473G 2.24T 33% - 17% 1.00x ONLINE - test 1.98G 89.5K 1.98G 48% - 0% 1.00x ONLINE -
The following command lists all the properties for a pool.
#
zpool get all pool
pool size 2.70T - pool capacity 17% - pool altroot - default pool health ONLINE - pool guid 2501120270416322443 default pool version 28 default pool bootfs pool/root local pool delegation on default pool autoreplace off default pool cachefile - default pool failmode wait default pool listsnapshots off default pool autoexpand off default pool dedupditto 0 default pool dedupratio 1.00x - pool free 2.24T - pool allocated 473G - pool readonly off -
The following command destroys the pool “tank” and any datasets contained within.
#
zpool destroy -f tank
The following command exports the devices in pool tank so that they can be relocated or later imported.
#
zpool export tank
The following command displays available pools, and then imports the pool “tank” for use on the system.
The results from this command are similar to the following:
#
zpool import
pool: tank id: 15451357997522795478 state: ONLINE action: The pool can be imported using its name or numeric identifier. config: tank ONLINE mirror ONLINE da0 ONLINE da1 ONLINE
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 28.
The following command creates a new pool with an available hot spare:
#
zpool create tank mirror da0 da1 spare da2
If one of the disks were to fail, the pool would be reduced to the degraded state. The failed device can be replaced using the following command:
#
zpool replace tank da0 da2
Once the data has been resilvered, the spare is automatically removed and is made available should another device fails. The hot spare can be permanently removed from the pool using the following command:
#
zpool remove tank da2
The following command creates a ZFS storage pool consisting of two, two-way mirrors and mirrored log devices:
#
zpool create pool mirror da0 da1 mirror da2 da3 log mirror da4 da5
The following command adds two disks for use as cache devices to a ZFS storage pool:
#
zpool add pool cache da2 da3
Once added, the cache devices gradually fill with content from
main memory. Depending on the size of your cache devices, it could take
over an hour for them to fill. Capacity and reads can be monitored using
the iostat
subcommand as follows:
#
zpool iostat -v pool 5
The following command dipslays the detailed information for the data pool. This pool is comprised of a single raidz vdev where one of its devices increased its capacity by 10GB. In this example, the pool will not be able to utilized this extra capacity until all the devices under the raidz vdev have been expanded.
#
zpool list -v data
NAME SIZE ALLOC FREE FRAG EXPANDSZ CAP DEDUP HEALTH ALTROOT data 23.9G 14.6G 9.30G 48% - 61% 1.00x ONLINE - raidz1 23.9G 14.6G 9.30G 48% - ada0 - - - - - ada1 - - - - 10G ada2 - - - - -
The following command removes the mirrored log device mirror-2.
Given this configuration:
pool: tank state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 da0 ONLINE 0 0 0 da1 ONLINE 0 0 0 mirror-1 ONLINE 0 0 0 da2 ONLINE 0 0 0 da3 ONLINE 0 0 0 logs mirror-2 ONLINE 0 0 0 da4 ONLINE 0 0 0 da5 ONLINE 0 0 0
The command to remove the mirrored log mirror-2 is:
#
zpool remove tank mirror-2
If a pool is faulted but recoverable, a message indicating
this state is provided by “zpool
status
” if the pool was cached (see the
-c
cachefile argument
above), or as part of the error output from a failed
“zpool
import
” of the pool.
Recover a cached pool with the
“zpool
clear
” command:
#
zpool clear -F data
Pool data returned to its state as of Tue Sep 08 13:23:35 2009. Discarded approximately 29 seconds of transactions.
If the pool configuration was not cached, use
“zpool
import
” with the recovery mode flag:
#
zpool import -F data
Pool data returned to its state as of Tue Sep 08 13:23:35 2009. Discarded approximately 29 seconds of transactions.
The mdoc(7) implementation of this manual page was initially written by Martin Matuska ⟨mm@FreeBSD.org⟩.
July 26, 2014 | NetBSD 9.4 |