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-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.

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:

Example 2: Creating a Mirrored Storage Pool¶

The following command creates a pool with two mirrors, where each mirror contains two disks:

Example 3: Creating a ZFS Storage Pool by Using Partitions¶

The following command creates a non-redundant pool using two disk partitions:

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.

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.

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.

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:

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:

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:

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:

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:

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:

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:

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:

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:

The command to remove the mirrored data mirror-1 is:

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
----------  -----  -----  -----  -----  -----  -----  ----