zfs - Man Page

• List all available zfs filesystems: zfs list
• Create a new ZFS filesystem: zfs create pool_name/filesystem_name
• Delete a ZFS filesystem: zfs destroy pool_name/filesystem_name
• Create a Snapshot of a ZFS filesystem: zfs snapshot pool_name/filesystem_name@snapshot_name
• Enable compression on a filesystem: zfs set compression=on pool_name/filesystem_name
• Change mountpoint for a filesystem: zfs set mountpoint=/my/mount/path pool_name/filesystem_name

tldr.sh

zfs [-?]

zfs create [-p] [-o property=value] ... filesystem

zfs create [-ps] [-b blocksize] [-o property=value] ... -V size volume

zfs destroy [-rRf] filesystem|volume

zfs destroy [-rRd] snapshot

zfs snapshot [-r] [-o property=value]... 
      filesystem@snapname|volume@snapname

zfs rollback [-rRf] snapshot

zfs clone [-p] [-o property=value] ... snapshot filesystem|volume

zfs promote clone-filesystem

zfs rename filesystem|volume|snapshot 
     filesystem|volume|snapshot

zfs rename [-p] filesystem|volume filesystem|volume

zfs rename -r snapshot snapshot

zfs list [-r|-d depth][-H][-o property[,...]] [-t type[,...]]
     [-s property] ... [-S property] ... [filesystem|volume|snapshot] ...

zfs set property=value filesystem|volume|snapshot ...

zfs get [-r|-d depth][-Hp][-o all | field[,...]] [-s source[,...]]
     all | property[,...] filesystem|volume|snapshot ...

zfs inherit [-rS] property filesystem|volume|snapshot ...

zfs upgrade [-v]

zfs upgrade [-r] [-V version] -a | filesystem

zfs userspace [-niHp] [-o field[,...]] [-sS field] ...
     [-t type [,...]] filesystem|snapshot

zfs groupspace [-niHp] [-o field[,...]] [-sS field] ...
     [-t type [,...]] filesystem|snapshot

zfs mount

zfs mount [-vO] [-o options] -a | filesystem

zfs unmount [-f] -a | filesystem|mountpoint

zfs share -a | filesystem

zfs unshare -a filesystem|mountpoint

zfs send [-DvRp] [-[iI] snapshot] snapshot

zfs receive [-vnFu] filesystem|volume|snapshot

zfs receive [-vnFu] [-d | -e] filesystem

zfs allow filesystem|volume

zfs allow [-ldug] "everyone"|user|group[,...] perm|@setname[,...] 
     filesystem|volume

zfs allow [-ld] -e perm|@setname[,...] filesystem|volume

zfs allow -c perm|@setname[,...] filesystem|volume

zfs allow -s @setname perm|@setname[,...] filesystem|volume

zfs unallow [-rldug] "everyone"|user|group[,...] [perm|@setname[,... ]] 
     filesystem|volume

zfs unallow [-rld] -e [perm|@setname[,... ]] filesystem|volume

zfs unallow [-r] -c [perm|@setname[ ... ]] filesystem|volume

zfs unallow [-r] -s @setname [perm|@setname[,... ]] filesystem|volume

zfs hold [-r] tag snapshot...

zfs holds [-r] snapshot...

zfs release [-r] tag snapshot...

The zfs command configures ZFS datasets within a ZFS storage pool, as described in zpool(1M). A dataset is identified by a unique path within the ZFS namespace. For example:

pool/{filesystem,volume,snapshot}

where the maximum length of a dataset name is MAXNAMELEN (256 bytes).

A dataset can be one of the following:

file system

volume

A logical volume exported as a raw or block device. This type of dataset should only be used under special circumstances. 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.

1536M, 1.5g, 1.50GB

    PROPERTY                MOUNT OPTION
     devices                 devices/nodevices
     exec                    exec/noexec
     readonly                ro/rw
     setuid                  setuid/nosetuid
     xattr                   xattr/noxattr

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

zfs ?

Displays a help message.

zfs create [-p] [-o property=value] ... filesystem

Creates a new ZFS file system. The file system is automatically mounted according to the mountpoint property inherited from the parent.

-p

Creates all the non-existing parent datasets. Datasets created in this manner are automatically mounted according to the mountpoint property inherited from their parent. Any property specified on the command line using the -o option is ignored. If the target filesystem already exists, the operation completes successfully.

-o property=value

Sets the specified property as if the command zfs set property=value was invoked at the same time the dataset was created. Any editable ZFS property can also be set at creation time. Multiple -o options can be specified. An error results if the same property is specified in multiple -o options.

zfs create [-ps] [-b blocksize] [-o property=value] ... -V size volume

Creates a volume of the given size. The volume is exported as a block device in /dev/zvol/{dsk,rdsk}/path, where path is the name of the volume in the ZFS namespace. The size represents the logical size as exported by the device. By default, a reservation of equal size is created.

size is automatically rounded up to the nearest 128 Kbytes to ensure that the volume has an integral number of blocks regardless of blocksize.

-p

Creates all the non-existing parent datasets. Datasets created in this manner are automatically mounted according to the mountpoint property inherited from their parent. Any property specified on the command line using the -o option is ignored. If the target filesystem already exists, the operation completes successfully.

-s

Creates a sparse volume with no reservation. See volsize in the Native Properties section for more information about sparse volumes.

-o property=value

Sets the specified property as if the zfs set property=value command was invoked at the same time the dataset was created. Any editable ZFS property can also be set at creation time. Multiple -o options can be specified. An error results if the same property is specified in multiple -o options.

-b blocksize

Equivalent to -o volblocksize=blocksize. If this option is specified in conjunction with -o volblocksize, the resulting behavior is undefined.

zfs destroy [-rRf] filesystem|volume

Destroys the given dataset. By default, the command unshares any file systems that are currently shared, unmounts any file systems that are currently mounted, and refuses to destroy a dataset that has active dependents (children or clones).

-r

Recursively destroy all children.

-R

Recursively destroy all dependents, including cloned file systems outside the target hierarchy.

-f

Force an unmount of any file systems using the unmount -f command. This option has no effect on non-file systems or unmounted file systems.

Extreme care should be taken when applying either the -r or the -f options, as they can destroy large portions of a pool and cause unexpected behavior for mounted file systems in use.

zfs destroy [-rRd] snapshot

The given snapshot is destroyed immediately if and only if the zfs destroy command without the -d option would have destroyed it. Such immediate destruction would occur, for example, if the snapshot had no clones and the user-initiated reference count were zero.

If the snapshot does not qualify for immediate destruction, it is marked for deferred deletion. In this state, it exists as a usable, visible snapshot until both of the preconditions listed above are met, at which point it is destroyed.

-d

Defer snapshot deletion.

-r

Destroy (or mark for deferred deletion) all snapshots with this name in descendent file systems.

-R

Recursively destroy all dependents.

zfs snapshot [-r] [-o property=value] ... filesystem@snapname|volume@snapname

Creates a snapshot with the given name. All previous modifications by successful system calls to the file system are part of the snapshot. See the "Snapshots" section for details.

-r

Recursively create snapshots of all descendent datasets. Snapshots are taken atomically, so that all recursive snapshots correspond to the same moment in time.

-o property=value

Sets the specified property; see zfs create for details.

zfs rollback [-rRf] snapshot

Roll back the given dataset to a previous snapshot. When a dataset is rolled back, all data that has changed since the snapshot is discarded, and the dataset reverts to the state at the time of the snapshot. By default, the command refuses to roll back to a snapshot other than the most recent one. In order to do so, all intermediate snapshots must be destroyed by specifying the -r option.

The -rR options do not recursively destroy the child snapshots of a recursive snapshot. Only the top-level recursive snapshot is destroyed by either of these options. To completely roll back a recursive snapshot, you must rollback the individual child snapshots.

-r

Recursively destroy any snapshots more recent than the one specified.

-R

Recursively destroy any more recent snapshots, as well as any clones of those snapshots.

-f

Used with the -R option to force an unmount of any clone file systems that are to be destroyed.

zfs clone [-p] [-o property=value] ... snapshot filesystem|volume

Creates a clone of the given snapshot. See the "Clones" section for details. The target dataset can be located anywhere in the ZFS hierarchy, and is created as the same type as the original.

-p

Creates all the non-existing parent datasets. Datasets created in this manner are automatically mounted according to the mountpoint property inherited from their parent. If the target filesystem or volume already exists, the operation completes successfully.

-o property=value

Sets the specified property; see zfs create for details.

zfs promote clone-filesystem

Promotes a clone file system to no longer be dependent on its "origin" snapshot. This makes it possible to destroy the file system that the clone was created from. The clone parent-child dependency relationship is reversed, so that the origin file system becomes a clone of the specified file system.

The snapshot that was cloned, and any snapshots previous to this snapshot, are now owned by the promoted clone. The space they use moves from the origin file system to the promoted clone, so enough space must be available to accommodate these snapshots. No new space is consumed by this operation, but the space accounting is adjusted. The promoted clone must not have any conflicting snapshot names of its own. The rename subcommand can be used to rename any conflicting snapshots.

zfs rename filesystem|volume|snapshot

filesystem|volume|snapshot

zfs rename [-p] filesystem|volume filesystem|volume

Renames the given dataset. The new target can be located anywhere in the ZFS hierarchy, with the exception of snapshots. Snapshots can only be renamed within the parent file system or volume. When renaming a snapshot, the parent file system of the snapshot does not need to be specified as part of the second argument. Renamed file systems can inherit new mount points, in which case they are unmounted and remounted at the new mount point.

-p

Creates all the nonexistent parent datasets. Datasets created in this manner are automatically mounted according to the mountpoint property inherited from their parent.

zfs rename -r snapshot snapshot

Recursively rename the snapshots of all descendent datasets. Snapshots are the only dataset that can be renamed recursively.

zfs list [-r|-d depth] [-H] [-o property[,...]] [ -t type[,...]] [ -s property ] ... [ -S property ] ... [filesystem|volume|snapshot] ...

Lists the property information for the given datasets in tabular form. If specified, you can list property information by the absolute pathname or the relative pathname. By default, all file systems and volumes are displayed. Snapshots are displayed if the listsnaps property is on (the default is off) . The following fields are displayed, name,used,available,referenced,mountpoint.

-H

Used for scripting mode. Do not print headers and separate fields by a single tab instead of arbitrary white space.

-r

Recursively display any children of the dataset on the command line.

-d depth

Recursively display any children of the dataset, limiting the recursion to depth. A depth of 1 will display only the dataset and its direct children.

-o property

A comma-separated list of properties to display. The property must be:

• One of the properties described in the "Native Properties" section
• A user property
• The value name to display the dataset name
• The value space to display space usage properties on file systems and volumes. This is a shortcut for specifying -o name,avail,used,usedsnap,usedds,usedrefreserv,usedchild -t filesystem,volume syntax.

-s property

A property for sorting the output by column in ascending order based on the value of the property. The property must be one of the properties described in the "Properties" section, or the special value name to sort by the dataset name. Multiple properties can be specified at one time using multiple -s property options. Multiple -s options are evaluated from left to right in decreasing order of importance.

The following is a list of sorting criteria:

• Numeric types sort in numeric order.
• String types sort in alphabetical order.
• Types inappropriate for a row sort that row to the literal bottom, regardless of the specified ordering.
• If no sorting options are specified the existing behavior of zfs list is preserved.

-S property

Same as the -s option, but sorts by property in descending order.

-t type

A comma-separated list of types to display, where type is one of filesystem, snapshot , volume, or all. For example, specifying -t snapshot displays only snapshots.

zfs set property=value filesystem|volume|snapshot ...

Sets the property to the given value for each dataset. Only some properties can be edited. See the "Properties" section for more information on what properties can be set and acceptable values. Numeric values can be specified as exact values, or in a human-readable form with a suffix of B, K, M, G, T, P, E, Z (for bytes, kilobytes, megabytes, gigabytes, terabytes, petabytes, exabytes, or zettabytes, respectively). User properties can be set on snapshots. For more information, see the "User Properties" section.

zfs get [-r|-d depth] [-Hp] [-o all | field[,...] [-s source[,...]] all | property[,...] filesystem|volume|snapshot ...

Displays properties for the given datasets. If no datasets are specified, then the command displays properties for all datasets on the system. For each property, the following columns are displayed:

    name      Dataset name
     property  Property name
     value     Property value
     source    Property source. Can either be local, default,
               temporary, inherited, or none (-).

All columns except the RECEIVED column are displayed by default; specify particular or all columns, using the -o option. This command takes a comma-separated list of properties as described in the "Native Properties" and "User Properties" sections.

The special value all can be used to display all properties that apply to the given dataset's type (filesystem, volume, or snapshot).

-r

Recursively display properties for any children.

-d depth

Recursively display any children of the dataset, limiting the recursion to depth. A depth of 1 will display only the dataset and its direct children.

-H

Display output in a form more easily parsed by scripts. Any headers are omitted, and fields are explicitly separated by a single tab instead of an arbitrary amount of space.

-o field

Set of fields to display. One or more of:

name,property,value,received,source

Present multiple fields as a comma-separated list. The default value is:

name,property,value,source

The keyword all specifies all sources.

-s source

A comma-separated list of sources to display. Those properties coming from a source other than those in this list are ignored. Each source must be one of the following:

local,default,inherited,temporary,received,none

The default value is all sources.

-p

Display numbers in parseable (exact) values.

zfs inherit [-rS] property filesystem|volume|snapshot ...

Clears the specified property, causing it to be inherited from an ancestor. If no ancestor has the property set, then the default value is used. See the "Properties" section for a listing of default values, and details on which properties can be inherited.

-r

Recursively inherit the given property for all children.

-S

Revert to the received property value, if any. If the property does not have a received value, the behavior of zfs inherit -S is the same as zfs inherit without -S. If the property does have a received value, zfs inherit masks the received value with the inherited value until zfs inherit -S reverts to the received value.

zfs upgrade [-v]

Displays a list of file systems that are not the most recent version.

zfs upgrade [-r] [-V version] [-a | filesystem]

Upgrades file systems to a new on-disk version. Once this is done, the file systems will no longer be accessible on systems running older versions of the software. zfs send streams generated from new snapshots of these file systems cannot be accessed on systems running older versions of the software.

In general, the file system version is independent of the pool version. See zpool(1M) for information on the zpool upgrade command.

In some cases, the file system version and the pool version are interrelated and the pool version must be upgraded before the file system version can be upgraded.

-a

Upgrade all file systems on all imported pools.

filesystem

Upgrade the specified file system.

-r

Upgrade the specified file system and all descendent file systems

-V version

Upgrade to the specified version. If the -V flag is not specified, this command upgrades to the most recent version. This option can only be used to increase the version number, and only up to the most recent version supported by this software.

zfs userspace [-niHp] [-o field[,...]] [-sS field]... [-t type [,...]] filesystem | snapshot

Displays space consumed by, and quotas on, each user in the specified filesystem or snapshot. This corresponds to the userused@user and userquota@user properties.

-n

Print numeric ID instead of user/group name.

-H

Do not print headers, use tab-delimited output.

-p

Use exact (parseable) numeric output.

-o field[,...]

Display only the specified fields from the following set, type,name,used,quota.The default is to display all fields.

-s field

Sort output by this field. The s and S flags may be specified multiple times to sort first by one field, then by another. The default is -s type -s name.

-S field

Sort by this field in reverse order. See -s.

-t type[,...]

Print only the specified types from the following set, all,posixuser,smbuser,posixgroup,smbgroup.

The default is -t posixuser,smbuser

The default can be changed to include group types.

-i

Translate SID to POSIX ID. The POSIX ID may be ephemeral if no mapping exists. Normal POSIX interfaces (for example, stat(2), ls -l) perform this translation, so the -i option allows the output from zfs userspace to be compared directly with those utilities. However, -i may lead to confusion if some files were created by an SMB user before a SMB-to-POSIX name mapping was established. In such a case, some files are owned by the SMB entity and some by the POSIX entity. However, the -i option will report that the POSIX entity has the total usage and quota for both.

zfs groupspace [-niHp] [-o field[,...]] [-sS field]... [-t type [,...]] filesystem | snapshot

Displays space consumed by, and quotas on, each group in the specified filesystem or snapshot. This subcommand is identical to zfs userspace, except that the default types to display are -t posixgroup,smbgroup.

-

zfs mount

Displays all ZFS file systems currently mounted.

zfs mount [-vO] [-o options] -a | filesystem

Mounts ZFS file systems. Invoked automatically as part of the boot process.

-o options

An optional, comma-separated list of mount options to use temporarily for the duration of the mount. See the "Temporary Mount Point Properties" section for details.

-O

Perform an overlay mount. See mount(1M) for more information.

-v

Report mount progress.

-a

Mount all available ZFS file systems. Invoked automatically as part of the boot process.

filesystem

Mount the specified filesystem.

zfs unmount [-f] -a | filesystem|mountpoint

Unmounts currently mounted ZFS file systems. Invoked automatically as part of the shutdown process.

-f

Forcefully unmount the file system, even if it is currently in use.

-a

Unmount all available ZFS file systems. Invoked automatically as part of the boot process.

filesystem|mountpoint

Unmount the specified filesystem. The command can also be given a path to a ZFS file system mount point on the system.

zfs share -a | filesystem

Shares available ZFS file systems.

-a

Share all available ZFS file systems. Invoked automatically as part of the boot process.

filesystem

Share the specified filesystem according to the sharenfs and sharesmb properties. File systems are shared when the sharenfs or sharesmb property is set.

zfs unshare -a | filesystem|mountpoint

Unshares currently shared ZFS file systems. This is invoked automatically as part of the shutdown process.

-a

Unshare all available ZFS file systems. Invoked automatically as part of the boot process.

filesystem|mountpoint

Unshare the specified filesystem. The command can also be given a path to a ZFS file system shared on the system.

zfs send [-DvRp] [-[iI] snapshot] snapshot

Creates a stream representation of the second snapshot, which is written to standard output. The output can be redirected to a file or to a different system (for example, using ssh(1). By default, a full stream is generated.

-D

Perform dedup processing on the stream. Deduplicated streams cannot be received on systems that do not support the stream deduplication feature.

-i snapshot

Generate an incremental stream from the first snapshot to the second snapshot. The incremental source (the first snapshot) can be specified as the last component of the snapshot name (for example, the part after the @), and it is assumed to be from the same file system as the second snapshot.

If the destination is a clone, the source may be the origin snapshot, which must be fully specified (for example, pool/fs@origin, not just @origin).

-I snapshot

Generate a stream package that sends all intermediary snapshots from the first snapshot to the second snapshot. For example, -I @a fs@d is similar to -i @a fs@b; -i @b fs@c; -i @c fs@d. The incremental source snapshot may be specified as with the -i option.

-R

Generate a replication stream package, which will replicate the specified filesystem, and all descendent file systems, up to the named snapshot. When received, all properties, snapshots, descendent file systems, and clones are preserved.

If the -i or -I flags are used in conjunction with the -R flag, an incremental replication stream is generated. The current values of properties, and current snapshot and file system names are set when the stream is received. If the -F flag is specified when this stream is received, snapshots and file systems that do not exist on the sending side are destroyed.

-p

Send properties.

-v

Print verbose information about the stream package generated.

The format of the stream is committed. You will be able to receive your streams on future versions of ZFS.

zfs receive [-vnFu] filesystem|volume|snapshot

zfs receive [-vnFu] [-d | -e] filesystem

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 subcommand, which by default creates a full stream. zfs recv can be used as an alias for zfs receive.

If an incremental stream is received, then the destination file system must already exist, and its most recent snapshot must match the incremental stream's source. For zvols, the destination device link is destroyed and recreated, which means the zvol cannot be accessed during the receive operation.

When a snapshot replication package stream that is generated by using the zfs send -R command is  received, any snapshots that do not exist on the sending location are destroyed by using the zfs destroy -d command.

The name of the snapshot (and file system, if a full stream is received) that this subcommand creates depends on the argument type and the -d or -e option.

If the argument is a snapshot name, the specified snapshot is created. If the argument is a file system or volume name, a snapshot with the same name as the sent snapshot is created within the specified filesystem or volume. If the -d or -e option is specified, the snapshot name is determined by appending the sent snapshot's name to the specified filesystem. If the -d option is specified, all but the pool name of the sent snapshot path is appended (for example, b/c@1 appended from sent snapshot a/b/c@1), and if the -e option is specified, only the tail of the sent snapshot path is appended (for example, c@1 appended from sent snapshot a/b/c@1). In the case of -d, any file systems needed to replicate the path of the sent snapshot are created within the specified file system.

-d

Use all but the first element of the sent snapshot path (all but the pool name) to determine the name of the new snapshot as described in the paragraph above.

-e

Use the last element of the sent snapshot path to determine the name of the new snapshot as described in the paragraph above.

-u

File system that is associated with the received stream is not mounted.

-v

Print verbose information about the stream and the time required to perform the receive operation.

-n

Do not actually receive the stream. This can be useful in conjunction with the -v option to verify the name the receive operation would use.

-F

Force a rollback of the file system to the most recent snapshot before performing the receive operation. If receiving an incremental replication stream (for example, one generated by zfs send -R -[iI]), destroy snapshots and file systems that do not exist on the sending side.

zfs allow filesystem | volume

Displays permissions that have been delegated on the specified filesystem or volume. See the other forms of zfs allow for more information.

zfs allow [-ldug] "everyone"|user|group[,...] perm|@setname[,...] filesystem| volume

zfs allow [-ld] -e perm|@setname[,...] filesystem | volume

Delegates ZFS administration permission for the file systems to non-privileged users.

[-ug] "everyone"|user|group[,...]

Specifies to whom the permissions are delegated. Multiple entities can be specified as a comma-separated list. If neither of the -ug options are specified, then the argument is interpreted preferentially as the keyword "everyone", then as a user name, and lastly as a group name. To specify a user or group named "everyone", use the -u or -g options. To specify a group with the same name as a user, use the -g options.

[-e] perm|@setname[,...]

Specifies that the permissions be delegated to "everyone." Multiple permissions may be specified as a comma-separated list. Permission names are the same as ZFS subcommand and property names. See the property list below. Property set names, which begin with an at sign (@) , may be specified. See the -s form below for details.

[-ld] filesystem|volume

Specifies where the permissions are delegated. If neither of the -ld options are specified, or both are, then the permissions are allowed for the file system or volume, and all of its descendents. If only the -l option is used, then is allowed "locally" only for the specified file system. If only the -d option is used, then is allowed only for the descendent file systems.

Permissions are generally the ability to use a ZFS subcommand or change a ZFS property. The following permissions are available:

NAME             TYPE           NOTES
allow            subcommand     Must also have the permission that is
                                being allowed
clone            subcommand     Must also have the 'create' ability and
                                'mount'
                                ability in the origin file system
create           subcommand     Must also have the 'mount' ability
destroy          subcommand     Must also have the 'mount' ability
hold             subcommand     Allows adding a user hold to a snapshot
mount            subcommand     Allows mount/umount of ZFS datasets
promote          subcommand     Must also have the 'mount' and 'promote'
                                ability in the origin file system
receive          subcommand     Must also have the 'mount' and 'create'
                                ability
release          subcommand     Allows releasing a user hold which
                                might destroy the snapshot
rename           subcommand     Must also have the 'mount' and 'create'
                                ability in the new parent
rollback         subcommand
send             subcommand     
share            subcommand     Allows sharing file systems over NFS or
                                SMB protocols
snapshot         subcommand
groupquota       other          Allows accessing any groupquota@...
                                property
groupused        other          Allows reading any groupused@... property
userprop         other          Allows changing any user property
userquota        other          Allows accessing any userquota@...
                                property
userused         other          Allows reading any userused@... property
aclinherit       property       
aclmode          property       
atime            property       
canmount         property       
casesensitivity  property       
checksum         property       
compression      property       
copies           property       
dedup            property
devices          property       
exec             property       
logbias          property
mlslabel         property
mountpoint       property       
nbmand           property       
normalization    property       
primarycache     property       
quota            property       
readonly         property       
recordsize       property       
refquota         property       
refreservation   property       
reservation      property       
secondarycache   property       
setuid           property       
shareiscsi       property       
sharenfs         property       
sharesmb         property       
snapdir          property       
utf8only         property       
version          property       
volblocksize     property       
volsize          property       
vscan            property       
xattr            property       
zoned            property

zfs allow -c perm|@setname[,...] filesystem|volume

Sets "create time" permissions. These permissions are granted (locally) to the creator of any newly-created descendent file system.

zfs allow -s @setname perm|@setname[,...] filesystem|volume

Defines or adds permissions to a permission set. The set can be used by other zfs allow commands for the specified file system and its descendents. Sets are evaluated dynamically, so changes to a set are immediately reflected. Permission sets follow the same naming restrictions as ZFS file systems, but the name must begin with an "at sign" (@), and can be no more than 64 characters long.

zfs unallow [-rldug] "everyone"|user|group[,...] [perm|@setname[, ...]] filesystem|volume

zfs unallow [-rld] -e [perm|@setname [,...]] filesystem|volume

zfs unallow [-r] -c [perm|@setname[,...]]

filesystem|volume

Removes permissions that were granted with the zfs allow command. No permissions are explicitly denied, so other permissions granted are still in effect. For example, if the permission is granted by an ancestor. If no permissions are specified, then all permissions for the specified user, group, or everyone are removed. Specifying "everyone" (or using the -e option) only removes the permissions that were granted to "everyone", not all permissions for every user and group. See the zfs allow command for a description of the -ldugec options.

-r

Recursively remove the permissions from this file system and all descendents.

zfs unallow [-r] -s @setname [perm|@setname[,...]]

filesystem|volume

Removes permissions from a permission set. If no permissions are specified, then all permissions are removed, thus removing the set entirely.

zfs hold [-r] tag snapshot...

Adds a single reference, named with the tag argument, to the specified snapshot or snapshots. Each snapshot has its own tag namespace, and tags must be unique within that space.

If a hold exists on a snapshot, attempts to destroy that snapshot by using the zfs destroy command return EBUSY.

-r

Specifies that a hold with the given tag is applied recursively to the snapshots of all descendent file systems.

zfs holds [-r] snapshot...

Lists all existing user references for the given snapshot or snapshots.

-r

Lists the holds that are set on the named descendent snapshots, in addition to listing the holds on the named snapshot.

zfs release [-r] tag snapshot...

Removes a single reference, named with the tag argument, from the specified snapshot or snapshots. The tag must already exist for each snapshot.

If a hold exists on a snapshot, attempts to destroy that snapshot by using the zfs destroy command return EBUSY.

-r

Recursively releases a hold with the given tag on the snapshots of all descendent file systems.

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 the listsnaps property is on. The default is off. See zpool(1M) 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              Mon Nov  9 15:05 2009  -
pool/home/bob  used                  282M                   -
pool/home/bob  available             134G                   -
pool/home/bob  referenced            282M                   -
pool/home/bob  compressratio         1.00x                  -
pool/home/bob  mounted               yes                    -
pool/home/bob  quota                 none                   default
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  aclmode               groupmask              default
pool/home/bob  aclinherit            restricted             default
pool/home/bob  canmount              on                     default
pool/home/bob  shareiscsi            off                    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         282M                   -
pool/home/bob  usedbychildren        0                      -
pool/home/bob  usedbyrefreservation  0                      -
pool/home/bob  logbias               latency                default
pool/home/bob  dedup                 off                    default
pool/home/bob  mlslabel              none                   default

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@aand 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 Creating a ZFS Volume as an iSCSI Target Device

The following example shows how to create a ZFS volume as an iSCSI target.

# zfs create -V 2g pool/volumes/vol1
# zfs set shareiscsi=on pool/volumes/vol1
# iscsitadm list target
Target: pool/volumes/vol1
 iSCSI Name: 
 iqn.1986-03.com.sun:02:7b4b02a6-3277-eb1b-e686-a24762c52a8c
 Connections: 0

After the iSCSI target is created, set up the iSCSI initiator. For more information about the Solaris iSCSI initiator, see iscsitadm(1M).

Example 16 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@yesterday @5daysago
# zfs rename -r pool/users@yesterday @4daysago
# zfs rename -r pool/users@yesterday @3daysago
# zfs rename -r pool/users@yesterday @2daysago
# zfs rename -r pool/users@today @yesterday
# zfs snapshot -r pool/users@today

Example 17 Setting sharenfs Property Options on a ZFS File System

The following commands show how to set sharenfs property options to enable rw 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,root=neo' tank/home

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

Example 18 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
-------------------------------------------------------------
Local+Descendent permissions on (tank/cindys)
          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. Set an ACL similar to the following syntax to provide mount point access:

# chmod A+user:cindys:add_subdirectory:allow /tank/cindys

Example 19 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
-------------------------------------------------------------
Create time permissions on (tank/users)
          create,destroy
Local+Descendent permissions on (tank/users)
          group staff create,mount
-------------------------------------------------------------

Example 20 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
-------------------------------------------------------------
Permission sets on (tank/users)
        @pset create,destroy,mount,snapshot
Create time permissions on (tank/users)
        create,destroy
Local+Descendent permissions on (tank/users)
        group staff @pset,create,mount
-------------------------------------------------------------

Example 21 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
-------------------------------------------------------------
Local+Descendent permissions on (users/home)
        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 22 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
-------------------------------------------------------------
Permission sets on (tank/users)
        @pset create,destroy,mount,snapshot
Create time permissions on (tank/users)
        create,destroy
Local+Descendent permissions on (tank/users)
        group staff @pset,create,mount
-------------------------------------------------------------

The following exit values are returned:

0

Successful completion.

1

An error occurred.

2

Invalid command line options were specified.

See attributes(5) for descriptions of the following attributes:

ssh(1), iscsitadm(1M), mount(1M), share(1M), sharemgr(1M), unshare(1M), zonecfg(1M), zpool(1M), chmod(2), stat(2), write(2), fsync(3C), dfstab(4), attributes(5)

See the gzip(1) man page, which is not part of the SunOS man page collection.

For information about using the ZFS web-based management tool and other ZFS features, see the Solaris ZFS Administration Guide.

configuration.nix(5), growlight(8), growlight-readline(8), zdb(8), zfs-fuse(8).