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NAME

     zfs — configure ZFS datasets

SYNOPSIS

     zfs -?V
     zfs version
     zfs subcommand [arguments]

DESCRIPTION

     The zfs command configures ZFS datasets within a ZFS storage pool, as described in zpool(8).
     A dataset is identified by a unique path within the ZFS namespace:

           pool[/component]/component

     for example:

           rpool/var/log

     The maximum length of a dataset name is ZFS_MAX_DATASET_NAME_LEN - 1 ASCII characters
     (currently 255) satisfying [A-Za-z_.:/ -].  Additionally snapshots are allowed to contain a
     single @ character, while bookmarks are allowed to contain a single # character.  / is used
     as separator between components.  The maximum amount of nesting allowed in a path is
     zfs_max_dataset_nesting levels deep.  ZFS tunables (zfs_*) are explained in zfs(4).

     A dataset can be one of the following:

           file system  Can be mounted within the standard system namespace and behaves like
                        other file systems.  While ZFS file systems are designed to be POSIX-
                        compliant, known issues exist that prevent compliance in some cases.
                        Applications that depend on standards conformance might fail due to non-
                        standard behavior when checking file system free space.

           volume       A logical volume exported as a raw or block device.  This type of dataset
                        should only be used when a block device is required.  File systems are
                        typically used in most environments.

           snapshot     A read-only version of a file system or volume at a given point in time.
                        It is specified as filesystem@name or volume@name.

           bookmark     Much like a snapshot, but without the hold on on-disk data.  It can be
                        used as the source of a send (but not for a receive).  It is specified as
                        filesystem#name or volume#name.

     See zfsconcepts(7) for details.

   Properties
     Properties are divided into two types: native properties and user-defined (or "user")
     properties.  Native properties either export internal statistics or control ZFS behavior.
     In addition, native properties are either editable or read-only.  User properties have no
     effect on ZFS behavior, but you can use them to annotate datasets in a way that is
     meaningful in your environment.  For more information about properties, see zfsprops(7).

   Encryption
     Enabling the encryption feature allows for the creation of encrypted filesystems and
     volumes.  ZFS will encrypt file and zvol data, file attributes, ACLs, permission bits,
     directory listings, FUID mappings, and userused/groupused/projectused data.  For an overview
     of encryption, see zfs-load-key(8).

SUBCOMMANDS

     All subcommands that modify state are logged persistently to the pool in their original
     form.

     zfs -?
       Displays a help message.

     zfs -V, --version

     zfs version
       Displays the software version of the zfs userland utility and the zfs kernel module.

   Dataset Management
     zfs-list(8)
       Lists the property information for the given datasets in tabular form.

     zfs-create(8)
       Creates a new ZFS file system or volume.

     zfs-destroy(8)
       Destroys the given dataset(s), snapshot(s), or bookmark.

     zfs-rename(8)
       Renames the given dataset (filesystem or snapshot).

     zfs-upgrade(8)
       Manage upgrading the on-disk version of filesystems.

   Snapshots
     zfs-snapshot(8)
       Creates snapshots with the given names.

     zfs-rollback(8)
       Roll back the given dataset to a previous snapshot.

     zfs-hold(8)/zfs-release(8)
       Add or remove a hold reference to the specified snapshot or snapshots.  If a hold exists
       on a snapshot, attempts to destroy that snapshot by using the zfs destroy command return
       EBUSY.

     zfs-diff(8)
       Display the difference between a snapshot of a given filesystem and another snapshot of
       that filesystem from a later time or the current contents of the filesystem.

   Clones
     zfs-clone(8)
       Creates a clone of the given snapshot.

     zfs-promote(8)
       Promotes a clone file system to no longer be dependent on its "origin" snapshot.

   Send & Receive
     zfs-send(8)
       Generate a send stream, which may be of a filesystem, and may be incremental from a
       bookmark.

     zfs-receive(8)
       Creates a snapshot whose contents are as specified in the stream provided on standard
       input.  If a full stream is received, then a new file system is created as well.  Streams
       are created using the zfs-send(8) subcommand, which by default creates a full stream.

     zfs-bookmark(8)
       Creates a new bookmark of the given snapshot or bookmark.  Bookmarks mark the point in
       time when the snapshot was created, and can be used as the incremental source for a zfs
       send command.

     zfs-redact(8)
       Generate a new redaction bookmark.  This feature can be used to allow clones of a
       filesystem to be made available on a remote system, in the case where their parent need
       not (or needs to not) be usable.

   Properties
     zfs-get(8)
       Displays properties for the given datasets.

     zfs-set(8)
       Sets the property or list of properties to the given value(s) for each dataset.

     zfs-inherit(8)
       Clears the specified property, causing it to be inherited from an ancestor, restored to
       default if no ancestor has the property set, or with the -S option reverted to the
       received value if one exists.

   Quotas
     zfs-userspace(8)/zfs-groupspace(8)/zfs-projectspace(8)
       Displays space consumed by, and quotas on, each user, group, or project in the specified
       filesystem or snapshot.

     zfs-project(8)
       List, set, or clear project ID and/or inherit flag on the files or directories.

   Mountpoints
     zfs-mount(8)
       Displays all ZFS file systems currently mounted, or mount ZFS filesystem on a path
       described by its mountpoint property.

     zfs-unmount(8)
       Unmounts currently mounted ZFS file systems.

   Shares
     zfs-share(8)
       Shares available ZFS file systems.

     zfs-unshare(8)
       Unshares currently shared ZFS file systems.

   Delegated Administration
     zfs-allow(8)
       Delegate permissions on the specified filesystem or volume.

     zfs-unallow(8)
       Remove delegated permissions on the specified filesystem or volume.

   Encryption
     zfs-change-key(8)
       Add or change an encryption key on the specified dataset.

     zfs-load-key(8)
       Load the key for the specified encrypted dataset, enabling access.

     zfs-unload-key(8)
       Unload a key for the specified dataset, removing the ability to access the dataset.

   Channel Programs
     zfs-program(8)
       Execute ZFS administrative operations programmatically via a Lua script-language channel
       program.

   Jails
     zfs-jail(8)
       Attaches a filesystem to a jail.

     zfs-unjail(8)
       Detaches a filesystem from a jail.

   Waiting
     zfs-wait(8)
       Wait for background activity in a filesystem to complete.

EXIT STATUS

     The zfs utility exits 0 on success, 1 if an error occurs, and 2 if invalid command line
     options were specified.

EXAMPLES

   Example 1: Creating a ZFS File System Hierarchy
     The following commands create a file system named pool/home and a file system named
     pool/home/bob.  The mount point /export/home is set for the parent file system, and is
     automatically inherited by the child file system.
           # zfs create pool/home
           # zfs set mountpoint=/export/home pool/home
           # zfs create pool/home/bob

   Example 2: Creating a ZFS Snapshot
     The following command creates a snapshot named yesterday.  This snapshot is mounted on
     demand in the .zfs/snapshot directory at the root of the pool/home/bob file system.
           # zfs snapshot pool/home/bob@yesterday

   Example 3: Creating and Destroying Multiple Snapshots
     The following command creates snapshots named yesterday of pool/home and all of its
     descendent file systems.  Each snapshot is mounted on demand in the .zfs/snapshot directory
     at the root of its file system.  The second command destroys the newly created snapshots.
           # zfs snapshot -r pool/home@yesterday
           # zfs destroy -r pool/home@yesterday

   Example 4: Disabling and Enabling File System Compression
     The following command disables the compression property for all file systems under
     pool/home.  The next command explicitly enables compression for pool/home/anne.
           # zfs set compression=off pool/home
           # zfs set compression=on pool/home/anne

   Example 5: Listing ZFS Datasets
     The following command lists all active file systems and volumes in the system.  Snapshots
     are displayed if listsnaps=on.  The default is off.  See zpoolprops(7) for more information
     on pool properties.
           # zfs list
           NAME                      USED  AVAIL  REFER  MOUNTPOINT
           pool                      450K   457G    18K  /pool
           pool/home                 315K   457G    21K  /export/home
           pool/home/anne             18K   457G    18K  /export/home/anne
           pool/home/bob             276K   457G   276K  /export/home/bob

   Example 6: Setting a Quota on a ZFS File System
     The following command sets a quota of 50 Gbytes for pool/home/bob:
           # zfs set quota=50G pool/home/bob

   Example 7: Listing ZFS Properties
     The following command lists all properties for pool/home/bob:
           # zfs get all pool/home/bob
           NAME           PROPERTY              VALUE                  SOURCE
           pool/home/bob  type                  filesystem             -
           pool/home/bob  creation              Tue Jul 21 15:53 2009  -
           pool/home/bob  used                  21K                    -
           pool/home/bob  available             20.0G                  -
           pool/home/bob  referenced            21K                    -
           pool/home/bob  compressratio         1.00x                  -
           pool/home/bob  mounted               yes                    -
           pool/home/bob  quota                 20G                    local
           pool/home/bob  reservation           none                   default
           pool/home/bob  recordsize            128K                   default
           pool/home/bob  mountpoint            /pool/home/bob         default
           pool/home/bob  sharenfs              off                    default
           pool/home/bob  checksum              on                     default
           pool/home/bob  compression           on                     local
           pool/home/bob  atime                 on                     default
           pool/home/bob  devices               on                     default
           pool/home/bob  exec                  on                     default
           pool/home/bob  setuid                on                     default
           pool/home/bob  readonly              off                    default
           pool/home/bob  zoned                 off                    default
           pool/home/bob  snapdir               hidden                 default
           pool/home/bob  acltype               off                    default
           pool/home/bob  aclmode               discard                default
           pool/home/bob  aclinherit            restricted             default
           pool/home/bob  canmount              on                     default
           pool/home/bob  xattr                 on                     default
           pool/home/bob  copies                1                      default
           pool/home/bob  version               4                      -
           pool/home/bob  utf8only              off                    -
           pool/home/bob  normalization         none                   -
           pool/home/bob  casesensitivity       sensitive              -
           pool/home/bob  vscan                 off                    default
           pool/home/bob  nbmand                off                    default
           pool/home/bob  sharesmb              off                    default
           pool/home/bob  refquota              none                   default
           pool/home/bob  refreservation        none                   default
           pool/home/bob  primarycache          all                    default
           pool/home/bob  secondarycache        all                    default
           pool/home/bob  usedbysnapshots       0                      -
           pool/home/bob  usedbydataset         21K                    -
           pool/home/bob  usedbychildren        0                      -
           pool/home/bob  usedbyrefreservation  0                      -

     The following command gets a single property value:
           # zfs get -H -o value compression pool/home/bob
           on

     The following command lists all properties with local settings for pool/home/bob:
           # zfs get -r -s local -o name,property,value all pool/home/bob
           NAME           PROPERTY              VALUE
           pool/home/bob  quota                 20G
           pool/home/bob  compression           on

   Example 8: Rolling Back a ZFS File System
     The following command reverts the contents of pool/home/anne to the snapshot named
     yesterday, deleting all intermediate snapshots:
           # zfs rollback -r pool/home/anne@yesterday

   Example 9: Creating a ZFS Clone
     The following command creates a writable file system whose initial contents are the same as
     pool/home/bob@yesterday.
           # zfs clone pool/home/bob@yesterday pool/clone

   Example 10: Promoting a ZFS Clone
     The following commands illustrate how to test out changes to a file system, and then replace
     the original file system with the changed one, using clones, clone promotion, and renaming:
           # zfs create pool/project/production
             populate /pool/project/production with data
           # zfs snapshot pool/project/production@today
           # zfs clone pool/project/production@today pool/project/beta
             make changes to /pool/project/beta and test them
           # zfs promote pool/project/beta
           # zfs rename pool/project/production pool/project/legacy
           # zfs rename pool/project/beta pool/project/production
             once the legacy version is no longer needed, it can be destroyed
           # zfs destroy pool/project/legacy

   Example 11: Inheriting ZFS Properties
     The following command causes pool/home/bob and pool/home/anne to inherit the checksum
     property from their parent.
           # zfs inherit checksum pool/home/bob pool/home/anne

   Example 12: Remotely Replicating ZFS Data
     The following commands send a full stream and then an incremental stream to a remote
     machine, restoring them into poolB/received/fs@a and poolB/received/fs@b, respectively.
     poolB must contain the file system poolB/received, and must not initially contain
     poolB/received/fs.
           # zfs send pool/fs@a |
               ssh host zfs receive poolB/received/fs@a
           # zfs send -i a pool/fs@b |
               ssh host zfs receive poolB/received/fs

   Example 13: Using the zfs receive -d Option
     The following command sends a full stream of poolA/fsA/fsB@snap to a remote machine,
     receiving it into poolB/received/fsA/fsB@snap.  The fsA/fsB@snap portion of the received
     snapshot's name is determined from the name of the sent snapshot.  poolB must contain the
     file system poolB/received.  If poolB/received/fsA does not exist, it is created as an empty
     file system.
           # zfs send poolA/fsA/fsB@snap |
               ssh host zfs receive -d poolB/received

   Example 14: Setting User Properties
     The following example sets the user-defined com.example:department property for a dataset:
           # zfs set com.example:department=12345 tank/accounting

   Example 15: Performing a Rolling Snapshot
     The following example shows how to maintain a history of snapshots with a consistent naming
     scheme.  To keep a week's worth of snapshots, the user destroys the oldest snapshot, renames
     the remaining snapshots, and then creates a new snapshot, as follows:
           # zfs destroy -r pool/users@7daysago
           # zfs rename -r pool/users@6daysago @7daysago
           # zfs rename -r pool/users@5daysago @6daysago
           # zfs rename -r pool/users@4daysago @5daysago
           # zfs rename -r pool/users@3daysago @4daysago
           # zfs rename -r pool/users@2daysago @3daysago
           # zfs rename -r pool/users@yesterday @2daysago
           # zfs rename -r pool/users@today @yesterday
           # zfs snapshot -r pool/users@today

   Example 16: Setting sharenfs Property Options on a ZFS File System
     The following commands show how to set sharenfs property options to enable read-write access
     for a set of IP addresses and to enable root access for system "neo" on the tank/home file
     system:
           # zfs set sharenfs='rw=@123.123.0.0/16:[::1],root=neo' tank/home

     If you are using DNS for host name resolution, specify the fully-qualified hostname.

   Example 17: Delegating ZFS Administration Permissions on a ZFS Dataset
     The following example shows how to set permissions so that user cindys can create, destroy,
     mount, and take snapshots on tank/cindys.  The permissions on tank/cindys are also
     displayed.
           # zfs allow cindys create,destroy,mount,snapshot tank/cindys
           # zfs allow tank/cindys
           ---- Permissions on tank/cindys --------------------------------------
           Local+Descendent permissions:
                   user cindys create,destroy,mount,snapshot

     Because the tank/cindys mount point permission is set to 755 by default, user cindys will be
     unable to mount file systems under tank/cindys.  Add an ACE similar to the following syntax
     to provide mount point access:
           # chmod A+user:cindys:add_subdirectory:allow /tank/cindys

   Example 18: Delegating Create Time Permissions on a ZFS Dataset
     The following example shows how to grant anyone in the group staff to create file systems in
     tank/users.  This syntax also allows staff members to destroy their own file systems, but
     not destroy anyone else's file system.  The permissions on tank/users are also displayed.
           # zfs allow staff create,mount tank/users
           # zfs allow -c destroy tank/users
           # zfs allow tank/users
           ---- Permissions on tank/users ---------------------------------------
           Permission sets:
                   destroy
           Local+Descendent permissions:
                   group staff create,mount

   Example 19: Defining and Granting a Permission Set on a ZFS Dataset
     The following example shows how to define and grant a permission set on the tank/users file
     system.  The permissions on tank/users are also displayed.
           # zfs allow -s @pset create,destroy,snapshot,mount tank/users
           # zfs allow staff @pset tank/users
           # zfs allow tank/users
           ---- Permissions on tank/users ---------------------------------------
           Permission sets:
                   @pset create,destroy,mount,snapshot
           Local+Descendent permissions:
                   group staff @pset

   Example 20: Delegating Property Permissions on a ZFS Dataset
     The following example shows to grant the ability to set quotas and reservations on the
     users/home file system.  The permissions on users/home are also displayed.
           # zfs allow cindys quota,reservation users/home
           # zfs allow users/home
           ---- Permissions on users/home ---------------------------------------
           Local+Descendent permissions:
                   user cindys quota,reservation
           cindys% zfs set quota=10G users/home/marks
           cindys% zfs get quota users/home/marks
           NAME              PROPERTY  VALUE  SOURCE
           users/home/marks  quota     10G    local

   Example 21: Removing ZFS Delegated Permissions on a ZFS Dataset
     The following example shows how to remove the snapshot permission from the staff group on
     the tank/users file system.  The permissions on tank/users are also displayed.
           # zfs unallow staff snapshot tank/users
           # zfs allow tank/users
           ---- Permissions on tank/users ---------------------------------------
           Permission sets:
                   @pset create,destroy,mount,snapshot
           Local+Descendent permissions:
                   group staff @pset

   Example 22: Showing the differences between a snapshot and a ZFS Dataset
     The following example shows how to see what has changed between a prior snapshot of a ZFS
     dataset and its current state.  The -F option is used to indicate type information for the
     files affected.
           # zfs diff -F tank/test@before tank/test
           M       /       /tank/test/
           M       F       /tank/test/linked      (+1)
           R       F       /tank/test/oldname -> /tank/test/newname
           -       F       /tank/test/deleted
           +       F       /tank/test/created
           M       F       /tank/test/modified

   Example 23: Creating a bookmark
     The following example creates a bookmark to a snapshot.  This bookmark can then be used
     instead of a snapshot in send streams.
           # zfs bookmark rpool@snapshot rpool#bookmark

   Example 24: Setting sharesmb Property Options on a ZFS File System
     The following example show how to share SMB filesystem through ZFS.  Note that a user and
     their password must be given.
           # smbmount //127.0.0.1/share_tmp /mnt/tmp -o
           user=workgroup/turbo,password=obrut,uid=1000

     Minimal /etc/samba/smb.conf configuration is required, as follows.

     Samba will need to bind to the loopback interface for the ZFS utilities to communicate with
     Samba.  This is the default behavior for most Linux distributions.

     Samba must be able to authenticate a user.  This can be done in a number of ways (passwd(5),
     LDAP, smbpasswd(5), &c.).  How to do this is outside the scope of this document – refer to
     smb.conf(5) for more information.

     See the USERSHARES section for all configuration options, in case you need to modify any
     options of the share afterwards.  Do note that any changes done with the net(8) command will
     be undone if the share is ever unshared (like via a reboot).

ENVIRONMENT VARIABLES

     ZFS_COLOR           Use ANSI color in zfs diff and zfs list output.

     ZFS_MOUNT_HELPER    Cause zfs mount to use mount(8) to mount ZFS datasets.  This option is
                         provided for backwards compatibility with older ZFS versions.

     ZFS_SET_PIPE_MAX    Tells zfs to set the maximum pipe size for sends/recieves.  Disabled by
                         default on Linux due to an unfixed deadlock in Linux's pipe size
                         handling code.

     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

     Committed.

SEE ALSO

     attr(1), gzip(1), ssh(1), chmod(2), fsync(2), stat(2), write(2), acl(5), attributes(5),
     exports(5), zfsconcepts(7), zfsprops(7), exportfs(8), mount(8), net(8), selinux(8),
     zfs-allow(8), zfs-bookmark(8), zfs-change-key(8), zfs-clone(8), zfs-create(8),
     zfs-destroy(8), zfs-diff(8), zfs-get(8), zfs-groupspace(8), zfs-hold(8), zfs-inherit(8),
     zfs-jail(8), zfs-list(8), zfs-load-key(8), zfs-mount(8), zfs-program(8), zfs-project(8),
     zfs-projectspace(8), zfs-promote(8), zfs-receive(8), zfs-redact(8), zfs-release(8),
     zfs-rename(8), zfs-rollback(8), zfs-send(8), zfs-set(8), zfs-share(8), zfs-snapshot(8),
     zfs-unallow(8), zfs-unjail(8), zfs-unload-key(8), zfs-unmount(8), zfs-unshare(8),
     zfs-upgrade(8), zfs-userspace(8), zfs-wait(8), zpool(8)