zfs(8) manual page

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` `# zfs` `# zfs`
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`
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` `# zfs`
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` `# zfs`
Example 5: Listing ZFS Datasets
	The following command lists all active file systems and volumes in the system. Snapshots are displayed if listsnaps= on. The default is off. See zpoolprops(7) for more information on pool properties. # zfs 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`
Example 7: Listing ZFS Properties
	The following command lists all properties for pool/home/bob: # zfs NAME PROPERTY VALUE SOURCE pool/home/bob type filesystem - pool/home/bob creation Tue Jul 21 15:53 2009 - pool/home/bob used 21K - pool/home/bob available 20.0G - pool/home/bob referenced 21K - pool/home/bob compressratio 1.00x - pool/home/bob mounted yes - pool/home/bob quota 20G local pool/home/bob reservation none default pool/home/bob recordsize 128K default pool/home/bob mountpoint /pool/home/bob default pool/home/bob sharenfs off default pool/home/bob checksum on default pool/home/bob compression on local pool/home/bob atime on default pool/home/bob devices on default pool/home/bob exec on default pool/home/bob setuid on default pool/home/bob readonly off default pool/home/bob zoned off default pool/home/bob snapdir hidden default pool/home/bob acltype off default pool/home/bob aclmode discard default pool/home/bob aclinherit restricted default pool/home/bob canmount on default pool/home/bob xattr on default pool/home/bob copies 1 default pool/home/bob version 4 - pool/home/bob utf8only off - pool/home/bob normalization none - pool/home/bob casesensitivity sensitive - pool/home/bob vscan off default pool/home/bob nbmand off default pool/home/bob sharesmb off default pool/home/bob refquota none default pool/home/bob refreservation none default pool/home/bob primarycache all default pool/home/bob secondarycache all default pool/home/bob usedbysnapshots 0 - pool/home/bob usedbydataset 21K - pool/home/bob usedbychildren 0 - pool/home/bob usedbyrefreservation 0 - The following command gets a single property value: # zfs on The following command lists all properties with local settings for pool/home/bob: # zfs 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`
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`
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 populate /pool/project/production with data # zfs # zfs make changes to /pool/project/beta and test them # zfs # zfs # zfs once the legacy version is no longer needed, it can be destroyed # zfs
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`
Example 12: Remotely Replicating ZFS Data
	The following commands send a full stream and then an incremental stream to a remote machine, restoring them into poolB/received/fs@a and poolB/received/fs@b, respectively. poolB must contain the file system poolB/received, and must not initially contain poolB/received/fs. # zfs ssh # zfs ssh
Example 13: Using the zfs
	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 ssh
Example 14: Setting User Properties
	The following example sets the user-defined com.example :department property for a dataset: `# zfs`
Example 15: Performing a Rolling Snapshot
	The following example shows how to maintain a history of snapshots with a consistent naming scheme. To keep a week's worth of snapshots, the user destroys the oldest snapshot, renames the remaining snapshots, and then creates a new snapshot, as follows: # zfs # zfs # zfs # zfs # zfs # zfs # zfs # zfs # zfs
Example 16: Setting sharenfs Property Options on a ZFS File System
	The following commands show how to set sharenfs property options to enable read-write access for a set of IP addresses and to enable root access for system "neo" on the tank/home file system: `# zfs` If you are using DNS for host name resolution, specify the fully-qualified hostname.
Example 17: Delegating ZFS Administration Permissions on a ZFS Dataset
	The following example shows how to set permissions so that user cindys can create, destroy, mount, and take snapshots on tank/cindys. The permissions on tank/cindys are also displayed. # zfs # zfs ---- Permissions on tank/cindys -------------------------------------- Local+Descendent permissions: user cindys create,destroy,mount,snapshot Because the tank/cindys mount point permission is set to 755 by default, user cindys will be unable to mount file systems under tank/cindys. Add an ACE similar to the following syntax to provide mount point access: `# chmod A+user:cindys:add_subdirectory:allow /tank/cindys`
Example 18: Delegating Create Time Permissions on a ZFS Dataset
	The following example shows how to grant anyone in the group staff to create file systems in tank/users. This syntax also allows staff members to destroy their own file systems, but not destroy anyone else's file system. The permissions on tank/users are also displayed. # zfs # zfs # zfs ---- Permissions on tank/users --------------------------------------- Permission sets: destroy Local+Descendent permissions: group staff create,mount
Example 19: Defining and Granting a Permission Set on a ZFS Dataset
	The following example shows how to define and grant a permission set on the tank/users file system. The permissions on tank/users are also displayed. # zfs # zfs # zfs ---- Permissions on tank/users --------------------------------------- Permission sets: @pset create,destroy,mount,snapshot Local+Descendent permissions: group staff @pset
Example 20: Delegating Property Permissions on a ZFS Dataset
	The following example shows to grant the ability to set quotas and reservations on the users/home file system. The permissions on users/home are also displayed. # zfs # zfs ---- Permissions on users/home --------------------------------------- Local+Descendent permissions: user cindys quota,reservation cindys% zfs set quota=10G users/home/marks cindys% zfs get quota users/home/marks NAME PROPERTY VALUE SOURCE users/home/marks quota 10G local
Example 21: Removing ZFS Delegated Permissions on a ZFS Dataset
	The following example shows how to remove the snapshot permission from the staff group on the tank/users file system. The permissions on tank/users are also displayed. # zfs # zfs ---- Permissions on tank/users --------------------------------------- Permission sets: @pset create,destroy,mount,snapshot Local+Descendent permissions: group staff @pset
Example 22: Showing the differences between a snapshot and a ZFS Dataset
	The following example shows how to see what has changed between a prior snapshot of a ZFS dataset and its current state. The -F option is used to indicate type information for the files affected. # zfs M / /tank/test/ M F /tank/test/linked (+1) R F /tank/test/oldname -> /tank/test/newname - F /tank/test/deleted + F /tank/test/created M F /tank/test/modified
Example 23: Creating a bookmark
	The following example create a bookmark to a snapshot. This bookmark can then be used instead of snapshot in send streams. `# zfs`
Example 24: Setting sharesmb Property Options on a ZFS File System
	The following example show how to share SMB filesystem through ZFS. Note that a user and their password must be given. `# smbmount` Minimal `/etc/samba/smb.conf` configuration is required, as follows. Samba will need to bind to the loopback interface for the ZFS utilities to communicate with Samba. This is the default behavior for most Linux distributions. Samba must be able to authenticate a user. This can be done in a number of ways (passwd(5), LDAP,smbpasswd(5), &c.amp;). How to do this is outside the scope of this document â refer to smb.conf(5) for more information. See the USERSHARES section for all configuration options, in case you need to modify any options of the share afterwards. Do note that any changes done with the net(8) command will be undone if the share is ever unshared (like via a reboot).

file system	Can be mounted within the standard system namespace and behaves like other file systems. While ZFS file systems are designed to be POSIX-compliant, known issues exist that prevent compliance in some cases. Applications that depend on standards conformance might fail due to non-standard behavior when checking file system free space.
volume	A logical volume exported as a raw or block device. This type of dataset should only be used when a block device is required. File systems are typically used in most environments.
snapshot	A read-only version of a file system or volume at a given point in time. It is specified as filesystem@name or volume@name.
bookmark	Much like a snapshot, but without the hold on on-disk data. It can be used as the source of a send (but not for a receive). It is specified as filesystem#name or volume#name.

Fl	Displays a help message.
zfs -V -, --version
zfs version Displays the software version of the zfs userland utility and the zfs kernel module.

zfs-list(8)
	Lists the property information for the given datasets in tabular form.
zfs-create(8)
	Creates a new ZFS file system or volume.
zfs-destroy(8)
	Destroys the given dataset(s), snapshot(s), or bookmark.
zfs-rename(8)
	Renames the given dataset (filesystem or snapshot).
zfs-upgrade(8)
	Manage upgrading the on-disk version of filesystems.

zfs-snapshot(8)
	Creates snapshots with the given names.
zfs-rollback(8)
	Roll back the given dataset to a previous snapshot.
zfs-hold(8)/zfs-release(8)
	Add or remove a hold reference to the specified snapshot or snapshots. If a hold exists on a snapshot, attempts to destroy that snapshot by using the zfs command return EBUSY.
zfs-diff(8)
	Display the difference between a snapshot of a given filesystem and another snapshot of that filesystem from a later time or the current contents of the filesystem.

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

Manual Pages — ZFS

NAME

CONTENTS

SYNOPSIS

DESCRIPTION

Properties

Encryption

SUBCOMMANDS

Dataset Management

Snapshots

Clones

Send & Receive

Properties

Quotas

Mountpoints

Shares

Delegated Administration

Encryption

Channel Programs

Jails

Waiting

EXIT STATUS

EXAMPLES

ENVIRONMENT VARIABLES

INTERFACE STABILITY

SEE ALSO

zfs-send(8)
	Generate a send stream, which may be of a filesystem, and may be incremental from a bookmark.
zfs-receive(8)
	Creates a snapshot whose contents are as specified in the stream provided on standard input. If a full stream is received, then a new file system is created as well. Streams are created using the zfs-send(8) subcommand, which by default creates a full stream.
zfs-bookmark(8)
	Creates a new bookmark of the given snapshot or bookmark. Bookmarks mark the point in time when the snapshot was created, and can be used as the incremental source for a zfs command.
zfs-redact(8)
	Generate a new redaction bookmark. This feature can be used to allow clones of a filesystem to be made available on a remote system, in the case where their parent need not (or needs to not) be usable.

zfs-get(8)
	Displays properties for the given datasets.
zfs-set(8)
	Sets the property or list of properties to the given value(s) for each dataset.
zfs-inherit(8)
	Clears the specified property, causing it to be inherited from an ancestor, restored to default if no ancestor has the property set, or with the -S option reverted to the received value if one exists.

zfs-userspace(8)/zfs-groupspace(8)/zfs-projectspace(8)
	Displays space consumed by, and quotas on, each user, group, or project in the specified filesystem or snapshot.
zfs-project(8)
	List, set, or clear project ID and/or inherit flag on the file(s) or directories.

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

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

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

zfs-change-key(8)
	Add or change an encryption key on the specified dataset.
zfs-load-key(8)
	Load the key for the specified encrypted dataset, enabling access.
zfs-unload-key(8)
	Unload a key for the specified dataset, removing the ability to access the dataset.

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

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

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

ZFS_COLOR
	Use ANSI color in zfs output.

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

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