NAME
zfs - configures ZFS file systems
SYNOPSIS
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...
DESCRIPTION
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
A ZFS dataset of type filesystem 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 nonstandard 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 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.
ZFS File System Hierarchy
A ZFS storage pool is a logical collection of devices that provide
space for datasets. A storage pool is also the root of the ZFS file
system hierarchy.
The root of the pool can be accessed as a file system, such as mounting
and unmounting, taking snapshots, and setting properties. The physical
storage characteristics, however, are managed by the zpool(1M) command.
See zpool(1M) for more information on creating and administering pools.
Snapshots
A snapshot is a read-only copy of a file system or volume. Snapshots
can be created extremely quickly, and initially consume no additional
space within the pool. As data within the active dataset changes, the
snapshot consumes more data than would otherwise be shared with the
active dataset.
Snapshots can have arbitrary names. Snapshots of volumes can be cloned
or rolled back, but cannot be accessed independently.
File system snapshots can be accessed under the .zfs/snapshot directory
in the root of the file system. Snapshots are automatically mounted on
demand and may be unmounted at regular intervals. The visibility of the
.zfs directory can be controlled by the snapdir property.
Clones
A clone is a writable volume or file system whose initial contents are
the same as another dataset. As with snapshots, creating a clone is
nearly instantaneous, and initially consumes no additional space.
Clones can only be created from a snapshot. When a snapshot is cloned,
it creates an implicit dependency between the parent and child. Even
though the clone is created somewhere else in the dataset hierarchy,
the original snapshot cannot be destroyed as long as a clone exists.
The origin property exposes this dependency, and the destroy command
lists any such dependencies, if they exist.
The clone parent-child dependency relationship can be reversed by using
the promote subcommand. This causes the "origin" file system to become
a clone of the specified file system, which makes it possible to
destroy the file system that the clone was created from.
Mount Points
Creating a ZFS file system is a simple operation, so the number of file
systems per system is likely to be numerous. To cope with this, ZFS
automatically manages mounting and unmounting file systems without the
need to edit the /etc/vfstab file. All automatically managed file
systems are mounted by ZFS at boot time.
By default, file systems are mounted under /path, where path is the
name of the file system in the ZFS namespace. Directories are created
and destroyed as needed.
A file system can also have a mount point set in the mountpoint
property. This directory is created as needed, and ZFS automatically
mounts the file system when the zfs mount -a command is invoked
(without editing /etc/vfstab). The mountpoint property can be
inherited, so if pool/home has a mount point of /export/stuff, then
pool/home/user automatically inherits a mount point of
/export/stuff/user.
A file system mountpoint property of none prevents the file system from
being mounted.
If needed, ZFS file systems can also be managed with traditional tools
(mount, umount, /etc/vfstab). If a file system's mount point is set to
legacy, ZFS makes no attempt to manage the file system, and the
administrator is responsible for mounting and unmounting the file
system.
Zones
A ZFS file system can be added to a non-global zone by using the
zonecfg add fs subcommand. A ZFS file system that is added to a non-
global zone must have its mountpoint property set to legacy.
The physical properties of an added file system are controlled by the
global administrator. However, the zone administrator can create,
modify, or destroy files within the added file system, depending on how
the file system is mounted.
A dataset can also be delegated to a non-global zone by using the
zonecfg add dataset subcommand. You cannot delegate a dataset to one
zone and the children of the same dataset to another zone. The zone
administrator can change properties of the dataset or any of its
children. However, the quota property is controlled by the global
administrator.
A ZFS volume can be added as a device to a non-global zone by using the
zonecfg add device subcommand. However, its physical properties can be
modified only by the global administrator.
For more information about zonecfg syntax, see zonecfg(1M).
After a dataset is delegated to a non-global zone, the zoned property
is automatically set. A zoned file system cannot be mounted in the
global zone, since the zone administrator might have to set the mount
point to an unacceptable value.
The global administrator can forcibly clear the zoned property, though
this should be done with extreme care. The global administrator should
verify that all the mount points are acceptable before clearing the
property.
Deduplication
Deduplication is the process for removing redundant data at the block-
level, reducing the total amount of data stored. If a file system has
the dedup property enabled, duplicate data blocks are removed
synchronously. The result is that only unique data is stored and
common components are shared among files.
Native 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
user properties, see the "User Properties" section, below.
Every dataset has a set of properties that export statistics about the
dataset as well as control various behaviors. Properties are inherited
from the parent unless overridden by the child. Some properties apply
only to certain types of datasets (file systems, volumes, or
snapshots).
The values of numeric properties can be specified using human-readable
suffixes (for example, k, KB, M, Gb, and so forth, up to Z for
zettabyte). The following are all valid (and equal) specifications:
1536M, 1.5g, 1.50GB
The values of non-numeric properties are case sensitive and must be
lowercase, except for mountpoint, sharenfs, and sharesmb.
The following native properties consist of read-only statistics about
the dataset. These properties can be neither set, nor inherited. Native
properties apply to all dataset types unless otherwise noted.
available
The amount of space available to the dataset and all its children,
assuming that there is no other activity in the pool. Because space
is shared within a pool, availability can be limited by any number
of factors, including physical pool size, quotas, reservations, or
other datasets within the pool.
This property can also be referred to by its shortened column name,
avail.
compressratio
The compression ratio achieved for this dataset, expressed as a
multiplier. Compression can be turned on by running: zfs set
compression=on dataset. The default value is off.
creation
The time this dataset was created.
defer_destroy
This property is on if the snapshot has been marked for deferred
destroy by using the zfs destroy -d command. Otherwise, the
property is off.
mounted
For file systems, indicates whether the file system is currently
mounted. This property can be either yes or no.
origin
For cloned file systems or volumes, the snapshot from which the
clone was created. The origin cannot be destroyed (even with the -r
or -f options) so long as a clone exists.
referenced
The amount of data that is accessible by this dataset, which may or
may not be shared with other datasets in the pool. When a snapshot
or clone is created, it initially references the same amount of
space as the file system or snapshot it was created from, since its
contents are identical.
This property can also be referred to by its shortened column name,
refer.
type
The type of dataset: filesystem, volume, or snapshot.
used
The amount of space consumed by this dataset and all its
descendents. This is the value that is checked against this
dataset's quota and reservation. The space used does not include
this dataset's reservation, but does take into account the
reservations of any descendent datasets. The amount of space that a
dataset consumes from its parent, as well as the amount of space
that are freed if this dataset is recursively destroyed, is the
greater of its space used and its reservation.
When snapshots (see the "Snapshots" section) are created, their
space is initially shared between the snapshot and the file system,
and possibly with previous snapshots. As the file system changes,
space that was previously shared becomes unique to the snapshot,
and counted in the snapshot's space used. Additionally, deleting
snapshots can increase the amount of space unique to (and used by)
other snapshots.
The amount of space used, available, or referenced does not take
into account pending changes. Pending changes are generally
accounted for within a few seconds. Committing a change to a disk
using fsync(3c) or O_SYNC does not necessarily guarantee that the
space usage information is updated immediately.
usedby*
The usedby* properties decompose the used properties into the
various reasons that space is used. Specifically, used =
usedbychildren + usedbydataset + usedbyrefreservation +,
usedbysnapshots. These properties are only available for datasets
created on zpool "version 13" pools.
usedbychildren
The amount of space used by children of this dataset, which would
be freed if all the dataset's children were destroyed.
usedbydataset
The amount of space used by this dataset itself, which would be
freed if the dataset were destroyed (after first removing any
refreservation and destroying any necessary snapshots or
descendents).
usedbyrefreservation
The amount of space used by a refreservation set on this dataset,
which would be freed if the refreservation was removed.
usedbysnapshots
The amount of space consumed by snapshots of this dataset. In
particular, it is the amount of space that would be freed if all of
this dataset's snapshots were destroyed. Note that this is not
simply the sum of the snapshots' used properties because space can
be shared by multiple snapshots.
userused@user
The amount of space consumed by the specified user in this dataset.
Space is charged to the owner of each file, as displayed by ls -l.
The amount of space charged is displayed by du and ls -s. See the
zfs userspace subcommand for more information.
Unprivileged users can access only their own space usage. The root
user, or a user who has been granted the userused privilege with
zfs allow, can access everyone's usage.
The userused@... properties are not displayed by zfs get all. The
user's name must be appended after the @ symbol, using one of the
following forms:
o POSIX name (for example, joe)
o POSIX numeric ID (for example, 789)
o SID name (for example, joe.smith@mydomain)
o SID numeric ID (for example, S-1-123-456-789)
userrefs
This property is set to the number of user holds on this snapshot.
User holds are set by using the zfs hold command.
groupused@group
The amount of space consumed by the specified group in this
dataset. Space is charged to the group of each file, as displayed
by ls -l. See the userused@user property for more information.
Unprivileged users can only access their own groups' space usage.
The root user, or a user who has been granted the groupused
privilege with zfs allow, can access all groups' usage.
volblocksize=blocksize
For volumes, specifies the block size of the volume. The blocksize
cannot be changed once the volume has been written, so it should be
set at volume creation time. The default blocksize for volumes is 8
Kbytes. Any power of 2 from 512 bytes to 128 Kbytes is valid.
This property can also be referred to by its shortened column name,
volblock.
The following native properties can be used to change the behavior of a
ZFS dataset.
aclinherit=discard | noallow | restricted | passthrough | passthrough-x
Controls how ACL entries are inherited when files and directories
are created. A file system with an aclinherit property of discard
does not inherit any ACL entries. A file system with an aclinherit
property value of noallow only inherits inheritable ACL entries
that specify "deny" permissions. The property value restricted (the
default) removes the write_acl and write_owner permissions when the
ACL entry is inherited. A file system with an aclinherit property
value of passthrough inherits all inheritable ACL entries without
any modifications made to the ACL entries when they are inherited.
A file system with an aclinherit property value of passthrough-x
has the same meaning as passthrough, except that the owner@,
group@, and everyone@ ACEs inherit the execute permission only if
the file creation mode also requests the execute bit.
When the property value is set to passthrough, files are created
with a mode determined by the inheritable ACEs. If no inheritable
ACEs exist that affect the mode, then the mode is set in accordance
to the requested mode from the application.
aclmode=discard | groupmask | passthrough
Controls how an ACL is modified during chmod(2). A file system with
an aclmode property of discard deletes all ACL entries that do not
represent the mode of the file. An aclmode property of groupmask
(the default) reduces user or group permissions. The permissions
are reduced, such that they are no greater than the group
permission bits, unless it is a user entry that has the same UID as
the owner of the file or directory. In this case, the ACL
permissions are reduced so that they are no greater than owner
permission bits. A file system with an aclmode property of
passthrough indicates that no changes are made to the ACL other
than generating the necessary ACL entries to represent the new mode
of the file or directory.
atime=on | off
Controls whether the access time for files is updated when they are
read. Turning this property off avoids producing write traffic when
reading files and can result in significant performance gains,
though it might confuse mailers and other similar utilities. The
default value is on.
canmount=on | off | noauto
If this property is set to off, the file system cannot be mounted,
and is ignored by zfs mount -a. Setting this property to off is
similar to setting the mountpoint property to none, except that the
dataset still has a normal mountpoint property, which can be
inherited. Setting this property to off allows datasets to be used
solely as a mechanism to inherit properties. One example of setting
canmount=off is to have two datasets with the same mountpoint, so
that the children of both datasets appear in the same directory,
but might have different inherited characteristics.
When the noauto option is set, a dataset can only be mounted and
unmounted explicitly. The dataset is not mounted automatically when
the dataset is created or imported, nor is it mounted by the zfs
mount -a command or unmounted by the zfs unmount -a command.
This property is not inherited.
checksum=on | off | fletcher2,| fletcher4 | sha256
Controls the checksum used to verify data integrity. The default
value is on, which automatically selects an appropriate algorithm
(currently, fletcher4, but this may change in future releases). The
value off disables integrity checking on user data. Disabling
checksums is NOT a recommended practice.
Changing this property affects only newly-written data.
compression=on | off | lzjb | gzip | gzip-N | zle
Controls the compression algorithm used for this dataset. The lzjb
compression algorithm is optimized for performance while providing
decent data compression. Setting compression to on uses the lzjb
compression algorithm. The gzip compression algorithm uses the same
compression as the gzip(1) command. You can specify the gzip level
by using the value gzip-N where N is an integer from 1 (fastest) to
9 (best compression ratio). Currently, gzip is equivalent to gzip-6
(which is also the default for gzip(1)).
This property can also be referred to by its shortened column name
compress. Changing this property affects only newly-written data.
copies=1 | 2 | 3
Controls the number of copies of data stored for this dataset.
These copies are in addition to any redundancy provided by the
pool, for example, mirroring or RAID-Z. The copies are stored on
different disks, if possible. The space used by multiple copies is
charged to the associated file and dataset, changing the used
property and counting against quotas and reservations.
Changing this property only affects newly-written data. Therefore,
set this property at file system creation time by using the -o
copies=N option.
dedup=on | off | verify | sha256[,verify]
Controls whether deduplication is in effect for a dataset. The
default value is off. The default checksum used for deduplication
is sha256 (subject to change). When dedup is enabled, the dedup
checksum algorithm overrides the checksum property. Setting the
value to verify is equivalent to specifying sha256,verify.
If the property is set to verify, then, whenever two blocks have
the same signature, ZFS will do a byte-for-byte comparison with the
existing block to ensure that the contents are identical.
devices=on | off
Controls whether device nodes can be opened on this file system.
The default value is on.
exec=on | off
Controls whether processes can be executed from within this file
system. The default value is on.
mlslabel=label | none
The mlslabel property is a sensitivity label that determines if a
dataset can be mounted in a zone on a system with Trusted
Extensions enabled. If the labeled dataset matches the labeled
zone, the dataset can be mounted and accessed from the labeled
zone.
When the mlslabel property is not set, the default value is none.
Setting the mlslabel property to none is equivalent to removing
the property.
The mlslabel property can be modified only when Trusted Extensions
is enabled and only with appropriate privilege. Rights to modify it
cannot be delegated. When changing a label to a higher label or
setting the initial dataset label, the {PRIV_FILE_UPGRADE_SL}
privilege is required. When changing a label to a lower label or
the default (none), the {PRIV_FILE_DOWNGRADE_SL} privilege is
required. Changing the dataset to labels other than the default can
be done only when the dataset is not mounted. When a dataset with
the default label is mounted into a labeled-zone, the mount
operation automatically sets the mlslabel property to the label of
that zone.
When Trusted Extensions is not enabled, only datasets with the
default label (none) can be mounted.
mountpoint=path | none | legacy
Controls the mount point used for this file system. See the "Mount
Points" section for more information on how this property is used.
When the mountpoint property is changed for a file system, the file
system and any children that inherit the mount point are unmounted.
If the new value is legacy, then they remain unmounted. Otherwise,
they are automatically remounted in the new location if the
property was previously legacy or none, or if they were mounted
before the property was changed. In addition, any shared file
systems are unshared and shared in the new location.
nbmand=on | off
Controls whether the file system should be mounted with nbmand (Non
Blocking mandatory locks). This is used for CIFS clients. Changes
to this property only take effect when the file system is umounted
and remounted. See mount(1M) for more information on nbmand mounts.
primarycache=all | none | metadata
Controls what is cached in the primary cache (ARC). If this
property is set to all, then both user data and metadata is cached.
If this property is set to none, then neither user data nor
metadata is cached. If this property is set to metadata, then only
metadata is cached. The default value is all.
quota=size | none
Limits the amount of space a dataset and its descendents can
consume. This property enforces a hard limit on the amount of space
used. This includes all space consumed by descendents, including
file systems and snapshots. Setting a quota on a descendent of a
dataset that already has a quota does not override the ancestor's
quota, but rather imposes an additional limit.
Quotas cannot be set on volumes, as the volsize property acts as an
implicit quota.
userquota@user=size | none
Limits the amount of space consumed by the specified user. Similar
to the refquota property, the userquota space calculation does not
include space that is used by descendent datasets, such as
snapshots and clones. User space consumption is identified by the
userspace@user property.
Enforcement of user quotas may be delayed by several seconds. This
delay means that a user might exceed her quota before the system
notices that she is over quota. The system would then begin to
refuse additional writes with the EDQUOT error message . See the
zfs userspace subcommand for more information.
Unprivileged users can only access their own groups' space usage.
The root user, or a user who has been granted the userquota
privilege with zfs allow, can get and set everyone's quota.
This property is not available on volumes, on file systems before
version 4, or on pools before version 15. The userquota@...
properties are not displayed by zfs get all. The user's name must
be appended after the @ symbol, using one of the following forms:
o POSIX name (for example, joe)
o POSIX numeric ID (for example, 789)
o SID name (for example, joe.smith@mydomain)
o SID numeric ID (for example, S-1-123-456-789)
groupquota@group=size | none
Limits the amount of space consumed by the specified group. Group
space consumption is identified by the userquota@user property.
Unprivileged users can access only their own groups' space usage.
The root user, or a user who has been granted the groupquota
privilege with zfs allow, can get and set all groups' quotas.
readonly=on | off
Controls whether this dataset can be modified. The default value is
off.
This property can also be referred to by its shortened column name,
rdonly.
recordsize=size
Specifies a suggested block size for files in the file system. This
property is designed solely for use with database workloads that
access files in fixed-size records. ZFS automatically tunes block
sizes according to internal algorithms optimized for typical access
patterns.
For databases that create very large files but access them in small
random chunks, these algorithms may be suboptimal. Specifying a
recordsize greater than or equal to the record size of the database
can result in significant performance gains. Use of this property
for general purpose file systems is strongly discouraged, and may
adversely affect performance.
The size specified must be a power of two greater than or equal to
512 and less than or equal to 128 Kbytes.
Changing the file system's recordsize affects only files created
afterward; existing files are unaffected.
This property can also be referred to by its shortened column name,
recsize.
refquota=size | none
Limits the amount of space a dataset can consume. This property
enforces a hard limit on the amount of space used. This hard limit
does not include space used by descendents, including file systems
and snapshots.
refreservation=size | none
The minimum amount of space guaranteed to a dataset, not including
its descendents. When the amount of space used is below this value,
the dataset is treated as if it were taking up the amount of space
specified by refreservation. The refreservation reservation is
accounted for in the parent datasets' space used, and counts
against the parent datasets' quotas and reservations.
If refreservation is set, a snapshot is only allowed if there is
enough free pool space outside of this reservation to accommodate
the current number of "referenced" bytes in the dataset.
This property can also be referred to by its shortened column name,
refreserv.
reservation=size | none
The minimum amount of space guaranteed to a dataset and its
descendents. When the amount of space used is below this value, the
dataset is treated as if it were taking up the amount of space
specified by its reservation. Reservations are accounted for in the
parent datasets' space used, and count against the parent datasets'
quotas and reservations.
This property can also be referred to by its shortened column name,
reserv.
secondarycache=all | none | metadata
Controls what is cached in the secondary cache (L2ARC). If this
property is set to all, then both user data and metadata is cached.
If this property is set to none, then neither user data nor
metadata is cached. If this property is set to metadata, then only
metadata is cached. The default value is all.
setuid=on | off
Controls whether the set-UID bit is respected for the file system.
The default value is on.
shareiscsi=on | off
Like the sharenfs property, shareiscsi indicates whether a ZFS
volume is exported as an iSCSI target. The acceptable values for
this property are on, off, and type=disk. The default value is off.
In the future, other target types might be supported. For example,
tape.
You might want to set shareiscsi=on for a file system so that all
ZFS volumes within the file system are shared by default. However,
setting this property on a file system has no direct effect.
sharesmb=on | off | opts
Controls whether the file system is shared by using the Solaris
CIFS service, and what options are to be used. A file system with
the sharesmb property set to off is managed through traditional
tools such as sharemgr(1M). Otherwise, the file system is
automatically shared and unshared with the zfs share and zfs
unshare commands. If the property is set to on, the sharemgr(1M)
command is invoked with no options. Otherwise, the sharemgr(1M)
command is invoked with options equivalent to the contents of this
property.
Because SMB shares requires a resource name, a unique resource name
is constructed from the dataset name. The constructed name is a
copy of the dataset name except that the characters in the dataset
name, which would be illegal in the resource name, are replaced
with underscore (_) characters. A pseudo property "name" is also
supported that allows you to replace the data set name with a
specified name. The specified name is then used to replace the
prefix dataset in the case of inheritance. For example, if the
dataset data/home/john is set to name=john, then data/home/john has
a resource name of john. If a child dataset of
data/home/john/backups, it has a resource name of john_backups.
When SMB shares are created, the SMB share name appears as an entry
in the .zfs/shares directory. You can use the ls or chmod command
to display the share-level ACLs on the entries in this directory.
When the sharesmb property is changed for a dataset, the dataset
and any children inheriting the property are re-shared with the new
options, only if the property was previously set to off, or if they
were shared before the property was changed. If the new property is
set to off, the file systems are unshared.
sharenfs=on | off | opts
Controls whether the file system is shared via NFS, and what
options are used. A file system with a sharenfs property of off is
managed through traditional tools such as share(1M), unshare(1M),
and dfstab(4). Otherwise, the file system is automatically shared
and unshared with the zfs share and zfs unshare commands. If the
property is set to on, the share(1M) command is invoked with no
options. Otherwise, the share(1M) command is invoked with options
equivalent to the contents of this property.
When the sharenfs property is changed for a dataset, the dataset
and any children inheriting the property are re-shared with the new
options, only if the property was previously off, or if they were
shared before the property was changed. If the new property is off,
the file systems are unshared.
logbias = latency | throughput
Provides a hint to ZFS about handling of synchronous requests in
this dataset. If logbias is set to latency (the default), ZFS uses
the pool's log devices (if configured) to handle the requests at
low latency. If logbias is set to throughput, ZFS does not use the
configured pool log devices. Instead, ZFS optimizes synchronous
operations for global pool throughput and efficient use of
resources.
snapdir=hidden | visible
Controls whether the .zfs directory is hidden or visible in the
root of the file system as discussed in the "Snapshots" section.
The default value is hidden.
version=1 | 2 | current
The on-disk version of this file system, which is independent of
the pool version. This property can only be set to later supported
versions. See the zfs upgrade command.
volsize=size
For volumes, specifies the logical size of the volume. By default,
creating a volume establishes a reservation of equal size. For
storage pools with a version number of 9 or higher, a
refreservation is set instead. Any changes to volsize are reflected
in an equivalent change to the reservation (or refreservation). The
volsize can only be set to a multiple of volblocksize, and cannot
be zero.
The reservation is kept equal to the volume's logical size to
prevent unexpected behavior for consumers. Without the reservation,
the volume could run out of space, resulting in undefined behavior
or data corruption, depending on how the volume is used. These
effects can also occur when the volume size is changed while it is
in use (particularly when shrinking the size). Extreme care should
be used when adjusting the volume size.
Though not recommended, a "sparse volume" (also known as "thin
provisioning") can be created by specifying the -s option to the
zfs create -V command, or by changing the reservation after the
volume has been created. A "sparse volume" is a volume where the
reservation is less then the volume size. Consequently, writes to a
sparse volume can fail with ENOSPC when the pool is low on space.
For a sparse volume, changes to volsize are not reflected in the
reservation.
vscan=on | off
Controls whether regular files should be scanned for viruses when a
file is opened and closed. In addition to enabling this property,
the virus scan service must also be enabled for virus scanning to
occur. The default value is off.
xattr=on | off
Controls whether extended attributes are enabled for this file
system. The default value is on.
zoned=on | off
Controls whether the dataset is managed from a non-global zone. See
the "Zones" section for more information. The default value is off.
The following three properties cannot be changed after the file system
is created, and therefore, should be set when the file system is
created. If the properties are not set with the zfs create or zpool
create commands, these properties are inherited from the parent
dataset. If the parent dataset lacks these properties due to having
been created prior to these features being supported, the new file
system will have the default values for these properties.
casesensitivity=sensitive | insensitive | mixed
Indicates whether the file name matching algorithm used by the file
system should be case-sensitive, case-insensitive, or allow a
combination of both styles of matching. The default value for the
casesensitivity property is sensitive. Traditionally, UNIX and
POSIX file systems have case-sensitive file names.
The mixed value for the casesensitivity property indicates that the
file system can support requests for both case-sensitive and case-
insensitive matching behavior. Currently, case-insensitive matching
behavior on a file system that supports mixed behavior is limited
to the Solaris CIFS server product. For more information about the
mixed value behavior, see the Solaris ZFS Administration Guide.
normalization = none | formC | formD | formKC | formKD
Indicates whether the file system should perform a unicode
normalization of file names whenever two file names are compared,
and which normalization algorithm should be used. File names are
always stored unmodified, names are normalized as part of any
comparison process. If this property is set to a legal value other
than none, and the utf8only property was left unspecified, the
utf8only property is automatically set to on. The default value of
the normalization property is none. This property cannot be changed
after the file system is created.
utf8only=on | off
Indicates whether the file system should reject file names that
include characters that are not present in the UTF-8 character code
set. If this property is explicitly set to off, the normalization
property must either not be explicitly set or be set to none. The
default value for the utf8only property is off. This property
cannot be changed after the file system is created.
The casesensitivity, normalization, and utf8only properties are also
new permissions that can be assigned to non-privileged users by using
the ZFS delegated administration feature.
Temporary Mount Point Properties
When a file system is mounted, either through mount(1M) for legacy
mounts or the zfs mount command for normal file systems, its mount
options are set according to its properties. The correlation between
properties and mount options is as follows:
PROPERTY MOUNT OPTION
devices devices/nodevices
exec exec/noexec
readonly ro/rw
setuid setuid/nosetuid
xattr xattr/noxattr
In addition, these options can be set on a per-mount basis using the -o
option, without affecting the property that is stored on disk. The
values specified on the command line override the values stored in the
dataset. The -nosuid option is an alias for nodevices,nosetuid. These
properties are reported as "temporary" by the zfs get command. If the
properties are changed while the dataset is mounted, the new setting
overrides any temporary settings.
User Properties
In addition to the standard native properties, ZFS supports arbitrary
user properties. User properties have no effect on ZFS behavior, but
applications or administrators can use them to annotate datasets (file
systems, volumes, and snapshots).
User property names must contain a colon (:) character to distinguish
them from native properties. They may contain lowercase letters,
numbers, and the following punctuation characters: colon (:), dash (-),
period (.), and underscore (_). The expected convention is that the
property name is divided into two portions such as module:property, but
this namespace is not enforced by ZFS. User property names can be at
most 256 characters, and cannot begin with a dash (-).
When making programmatic use of user properties, it is strongly
suggested to use a reversed DNS domain name for the module component of
property names to reduce the chance that two independently-developed
packages use the same property name for different purposes. Property
names beginning with com.sun. are reserved for use by Sun Microsystems.
The values of user properties are arbitrary strings, are always
inherited, and are never validated. All of the commands that operate on
properties (zfs list, zfs get, zfs set, and so forth) can be used to
manipulate both native properties and user properties. Use the zfs
inherit command to clear a user property . If the property is not
defined in any parent dataset, it is removed entirely. Property values
are limited to 1024 characters.
ZFS Volumes as Swap or Dump Devices
During an initial installation or a live upgrade from a UFS file
system, a swap device and dump device are created on ZFS volumes in the
ZFS root pool. By default, the swap area size is based on 1/2 the size
of physical memory up to 2 Gbytes. The size of the dump device depends
on the kernel's requirements at installation time. Separate ZFS volumes
must be used for the swap area and dump devices. Do not swap to a file
on a ZFS file system. A ZFS swap file configuration is not supported.
If you need to change your swap area or dump device after the system is
installed or upgraded, use the swap(1M) and dumpadm(1M) commands. If
you need to change the size of your swap area or dump device, see the
Solaris ZFS Administration Guide.
SUBCOMMANDS
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:
o One of the properties described in the "Native
Properties" section
o A user property
o The value name to display the dataset name
o 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:
o Numeric types sort in numeric order.
o String types sort in alphabetical order.
o Types inappropriate for a row sort that row to the
literal bottom, regardless of the specified
ordering.
o 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.
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 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
-------------------------------------------------------------
EXIT STATUS
The following exit values are returned:
0
Successful completion.
1
An error occurred.
2
Invalid command line options were specified.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWzfsu |
+-----------------------------+-----------------------------+
|Interface Stability |Committed |
+-----------------------------+-----------------------------+
SEE ALSO
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.