Provided by: zfsutils-linux_2.3.2-1ubuntu3_amd64 
NAME
zpool — configure ZFS storage pools
SYNOPSIS
zpool -?V
zpool version [-j]
zpool subcommand [arguments]
DESCRIPTION
The zpool command configures ZFS storage pools. A storage pool is a collection of devices that provides
physical storage and data replication for ZFS datasets. All datasets within a storage pool share the
same space. See zfs(8) for information on managing datasets.
For an overview of creating and managing ZFS storage pools see the zpoolconcepts(7) manual page.
SUBCOMMANDS
All subcommands that modify state are logged persistently to the pool in their original form.
The zpool command provides subcommands to create and destroy storage pools, add capacity to storage
pools, and provide information about the storage pools. The following subcommands are supported:
zpool -?
Displays a help message.
zpool -V, --version
zpool version [-j]
Displays the software version of the zpool userland utility and the ZFS kernel module. Use -j
option to output in JSON format.
Creation
zpool-create(8)
Creates a new storage pool containing the virtual devices specified on the command line.
zpool-initialize(8)
Begins initializing by writing to all unallocated regions on the specified devices, or all
eligible devices in the pool if no individual devices are specified.
Destruction
zpool-destroy(8)
Destroys the given pool, freeing up any devices for other use.
zpool-labelclear(8)
Removes ZFS label information from the specified device.
Virtual Devices
zpool-attach(8)/zpool-detach(8)
Converts a non-redundant disk into a mirror, or increases the redundancy level of an existing
mirror (attach), or performs the inverse operation ( detach).
zpool-add(8)/zpool-remove(8)
Adds the specified virtual devices to the given pool, or removes the specified device from the
pool.
zpool-replace(8)
Replaces an existing device (which may be faulted) with a new one.
zpool-split(8)
Creates a new pool by splitting all mirrors in an existing pool (which decreases its redundancy).
Properties
Available pool properties listed in the zpoolprops(7) manual page.
zpool-list(8)
Lists the given pools along with a health status and space usage.
zpool-get(8)/zpool-set(8)
Retrieves the given list of properties (or all properties if all is used) for the specified
storage pool(s).
Monitoring
zpool-status(8)
Displays the detailed health status for the given pools.
zpool-iostat(8)
Displays logical I/O statistics for the given pools/vdevs. Physical I/O operations may be
observed via iostat(1).
zpool-events(8)
Lists all recent events generated by the ZFS kernel modules. These events are consumed by the
zed(8) and used to automate administrative tasks such as replacing a failed device with a hot
spare. That manual page also describes the subclasses and event payloads that can be generated.
zpool-history(8)
Displays the command history of the specified pool(s) or all pools if no pool is specified.
Maintenance
zpool-prefetch(8)
Prefetches specific types of pool data.
zpool-scrub(8)
Begins a scrub or resumes a paused scrub.
zpool-checkpoint(8)
Checkpoints the current state of pool, which can be later restored by zpool import
--rewind-to-checkpoint.
zpool-trim(8)
Initiates an immediate on-demand TRIM operation for all of the free space in a pool. This
operation informs the underlying storage devices of all blocks in the pool which are no longer
allocated and allows thinly provisioned devices to reclaim the space.
zpool-sync(8)
This command forces all in-core dirty data to be written to the primary pool storage and not the
ZIL. It will also update administrative information including quota reporting. Without
arguments, zpool sync will sync all pools on the system. Otherwise, it will sync only the
specified pool(s).
zpool-upgrade(8)
Manage the on-disk format version of storage pools.
zpool-wait(8)
Waits until all background activity of the given types has ceased in the given pool.
Fault Resolution
zpool-offline(8)/zpool-online(8)
Takes the specified physical device offline or brings it online.
zpool-resilver(8)
Starts a resilver. If an existing resilver is already running it will be restarted from the
beginning.
zpool-reopen(8)
Reopen all the vdevs associated with the pool.
zpool-clear(8)
Clears device errors in a pool.
Import & Export
zpool-import(8)
Make disks containing ZFS storage pools available for use on the system.
zpool-export(8)
Exports the given pools from the system.
zpool-reguid(8)
Generates a new unique identifier for the pool.
EXIT STATUS
The following exit values are returned:
0 Successful completion.
1 An error occurred.
2 Invalid command line options were specified.
EXAMPLES
Example 1: Creating a RAID-Z Storage Pool
The following command creates a pool with a single raidz root vdev that consists of six disks:
# zpool create tank raidz sda sdb sdc sdd sde sdf
Example 2: Creating a Mirrored Storage Pool
The following command creates a pool with two mirrors, where each mirror contains two disks:
# zpool create tank mirror sda sdb mirror sdc sdd
Example 3: Creating a ZFS Storage Pool by Using Partitions
The following command creates a non-redundant pool using two disk partitions:
# zpool create tank sda1 sdb2
Example 4: Creating a ZFS Storage Pool by Using Files
The following command creates a non-redundant 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: Making a non-mirrored ZFS Storage Pool mirrored
The following command converts an existing single device sda into a mirror by attaching a second device
to it, sdb.
# zpool attach tank sda sdb
Example 6: Adding a Mirror to a ZFS Storage Pool
The following command adds two mirrored disks to the pool tank, assuming the pool is already made up of
two-way mirrors. The additional space is immediately available to any datasets within the pool.
# zpool add tank mirror sda sdb
Example 7: Listing Available ZFS Storage Pools
The following command lists all available pools on the system. In this case, the pool zion is faulted
due to a missing device. The results from this command are similar to the following:
# zpool list
NAME SIZE ALLOC FREE EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT
rpool 19.9G 8.43G 11.4G - 33% 42% 1.00x ONLINE -
tank 61.5G 20.0G 41.5G - 48% 32% 1.00x ONLINE -
zion - - - - - - - FAULTED -
Example 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: 15451357997522795478
state: ONLINE
action: The pool can be imported using its name or numeric identifier.
config:
tank ONLINE
mirror ONLINE
sda ONLINE
sdb ONLINE
# zpool import tank
Example 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 version 2.
Example 12: Managing Hot Spares
The following command creates a new pool with an available hot spare:
# zpool create tank mirror sda sdb spare sdc
If one of the disks were to fail, the pool would be reduced to the degraded state. The failed device can
be replaced using the following command:
# zpool replace tank sda sdd
Once the data has been resilvered, the spare is automatically removed and is made available for use
should another device fail. The hot spare can be permanently removed from the pool using the following
command:
# zpool remove tank sdc
Example 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 sda sdb mirror sdc sdd log mirror sde sdf
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 sdc sdd
Once added, the cache devices gradually fill with content from main memory. Depending on the size of
your cache devices, it could take over an hour for them to fill. Capacity and reads can be monitored
using the iostat subcommand as follows:
# zpool iostat -v pool 5
Example 15: Removing a Mirrored top-level (Log or Data) Device
The following commands remove the mirrored log device mirror-2 and mirrored top-level data device
mirror-1.
Given this configuration:
pool: tank
state: ONLINE
scrub: none requested
config:
NAME STATE READ WRITE CKSUM
tank ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
sda ONLINE 0 0 0
sdb ONLINE 0 0 0
mirror-1 ONLINE 0 0 0
sdc ONLINE 0 0 0
sdd ONLINE 0 0 0
logs
mirror-2 ONLINE 0 0 0
sde ONLINE 0 0 0
sdf ONLINE 0 0 0
The command to remove the mirrored log mirror-2 is:
# zpool remove tank mirror-2
At this point, the log device no longer exists (both sides of the mirror have been removed):
pool: tank
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
tank ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
sda ONLINE 0 0 0
sdb ONLINE 0 0 0
mirror-1 ONLINE 0 0 0
sdc ONLINE 0 0 0
sdd ONLINE 0 0 0
The command to remove the mirrored data mirror-1 is:
# zpool remove tank mirror-1
After mirror-1 has been evacuated, the pool remains redundant, but the total amount of space is reduced:
pool: tank
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
tank ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
sda ONLINE 0 0 0
sdb ONLINE 0 0 0
Example 16: Displaying expanded space on a device
The following command displays the detailed information for the pool data. This pool is comprised of a
single raidz vdev where one of its devices increased its capacity by 10 GiB. In this example, the pool
will not be able to utilize this extra capacity until all the devices under the raidz vdev have been
expanded.
# zpool list -v data
NAME SIZE ALLOC FREE EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT
data 23.9G 14.6G 9.30G - 48% 61% 1.00x ONLINE -
raidz1 23.9G 14.6G 9.30G - 48%
sda - - - - -
sdb - - - 10G -
sdc - - - - -
Example 17: Adding output columns
Additional columns can be added to the zpool status and zpool iostat output with -c.
# zpool status -c vendor,model,size
NAME STATE READ WRITE CKSUM vendor model size
tank ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
U1 ONLINE 0 0 0 SEAGATE ST8000NM0075 7.3T
U10 ONLINE 0 0 0 SEAGATE ST8000NM0075 7.3T
U11 ONLINE 0 0 0 SEAGATE ST8000NM0075 7.3T
U12 ONLINE 0 0 0 SEAGATE ST8000NM0075 7.3T
U13 ONLINE 0 0 0 SEAGATE ST8000NM0075 7.3T
U14 ONLINE 0 0 0 SEAGATE ST8000NM0075 7.3T
# zpool iostat -vc size
capacity operations bandwidth
pool alloc free read write read write size
---------- ----- ----- ----- ----- ----- ----- ----
rpool 14.6G 54.9G 4 55 250K 2.69M
sda1 14.6G 54.9G 4 55 250K 2.69M 70G
---------- ----- ----- ----- ----- ----- ----- ----
ENVIRONMENT VARIABLES
ZFS_ABORT Cause zpool to dump core on exit for the purposes of running
::findleaks.
ZFS_COLOR Use ANSI color in zpool status and zpool iostat output.
ZPOOL_AUTO_POWER_ON_SLOT Automatically attempt to turn on the drives enclosure slot power
to a drive when running the zpool online or zpool clear commands.
This has the same effect as passing the --power option to those
commands.
ZPOOL_POWER_ON_SLOT_TIMEOUT_MS The maximum time in milliseconds to wait for a slot power sysfs
value to return the correct value after writing it. For example,
after writing "on" to the sysfs enclosure slot power_control file,
it can take some time for the enclosure to power down the slot and
return "on" if you read back the 'power_control' value. Defaults
to 30 seconds (30000ms) if not set.
ZPOOL_IMPORT_PATH The search path for devices or files to use with the pool. This
is a colon-separated list of directories in which zpool looks for
device nodes and files. Similar to the -d option in zpool import.
ZPOOL_IMPORT_UDEV_TIMEOUT_MS The maximum time in milliseconds that zpool import will wait for
an expected device to be available.
ZPOOL_STATUS_NON_NATIVE_ASHIFT_IGNORE If set, suppress warning about non-native vdev ashift in zpool
status. The value is not used, only the presence or absence of
the variable matters.
ZPOOL_VDEV_NAME_GUID Cause zpool subcommands to output vdev GUIDs by default. This
behavior is identical to the zpool status -g command line option.
ZPOOL_VDEV_NAME_FOLLOW_LINKS Cause zpool subcommands to follow links for vdev names by default.
This behavior is identical to the zpool status -L command line
option.
ZPOOL_VDEV_NAME_PATH Cause zpool subcommands to output full vdev path names by default.
This behavior is identical to the zpool status -P command line
option.
ZFS_VDEV_DEVID_OPT_OUT Older OpenZFS implementations had issues when attempting to
display pool config vdev names if a devid NVP value is present in
the pool's config.
For example, a pool that originated on illumos platform would have
a devid value in the config and zpool status would fail when
listing the config. This would also be true for future Linux-
based pools.
A pool can be stripped of any devid values on import or prevented
from adding them on zpool create or zpool add by setting
ZFS_VDEV_DEVID_OPT_OUT.
ZPOOL_SCRIPTS_AS_ROOT Allow a privileged user to run zpool status/iostat -c. Normally,
only unprivileged users are allowed to run -c.
ZPOOL_SCRIPTS_PATH The search path for scripts when running zpool status/iostat -c.
This is a colon-separated list of directories and overrides the
default ~/.zpool.d and /etc/zfs/zpool.d search paths.
ZPOOL_SCRIPTS_ENABLED Allow a user to run zpool status/iostat -c. If
ZPOOL_SCRIPTS_ENABLED is not set, it is assumed that the user is
allowed to run zpool status/iostat -c.
ZFS_MODULE_TIMEOUT Time, in seconds, to wait for /dev/zfs to appear. Defaults to 10,
max 600 (10 minutes). If <0, wait forever; if 0, don't wait.
INTERFACE STABILITY
Evolving
SEE ALSO
zfs(4), zpool-features(7), zpoolconcepts(7), zpoolprops(7), zed(8), zfs(8), zpool-add(8),
zpool-attach(8), zpool-checkpoint(8), zpool-clear(8), zpool-create(8), zpool-ddtprune(8),
zpool-destroy(8), zpool-detach(8), zpool-events(8), zpool-export(8), zpool-get(8), zpool-history(8),
zpool-import(8), zpool-initialize(8), zpool-iostat(8), zpool-labelclear(8), zpool-list(8),
zpool-offline(8), zpool-online(8), zpool-prefetch(8), zpool-reguid(8), zpool-remove(8), zpool-reopen(8),
zpool-replace(8), zpool-resilver(8), zpool-scrub(8), zpool-set(8), zpool-split(8), zpool-status(8),
zpool-sync(8), zpool-trim(8), zpool-upgrade(8), zpool-wait(8)
OpenZFS February 14, 2024 ZPOOL(8)