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ZFS-LOAD-KEY(8) FreeBSD System Manager's Manual ZFS-LOAD-KEY(8)
NAME
zfs-load-key - load, unload, or change encryption key of ZFS dataset
SYNOPSIS
zfs load-key [-nr] [-L keylocation] -a|filesystem
zfs unload-key [-r] -a|filesystem
zfs change-key [-l] [-o keylocation=value] [-o keyformat=value]
[-o pbkdf2iters=value] filesystem
zfs change-key -i [-l] filesystem
DESCRIPTION
zfs load-key [-nr] [-L keylocation] -a|filesystem
Load the key for filesystem, allowing it and all children that inherit
the keylocation property to be accessed. The key will be expected in
the format specified by the keyformat and location specified by the
keylocation property. Note that if the keylocation is set to prompt
the terminal will interactively wait for the key to be entered.
Loading a key will not automatically mount the dataset. If that
functionality is desired, zfs mount -l will ask for the key and mount
the dataset (see zfs-mount(8)). Once the key is loaded the keystatus
property will become available.
-r Recursively loads the keys for the specified filesystem and all
descendent encryption roots.
-a Loads the keys for all encryption roots in all imported pools.
-n Do a dry-run ("No-op") load-key. This will cause zfs to simply
check that the provided key is correct. This command may be run
even if the key is already loaded.
-L keylocation
Use keylocation instead of the keylocation property. This will not
change the value of the property on the dataset. Note that if used
with either -r or -a, keylocation may only be given as prompt.
zfs unload-key [-r] -a|filesystem
Unloads a key from ZFS, removing the ability to access the dataset and
all of its children that inherit the keylocation property. This
requires that the dataset is not currently open or mounted. Once the
key is unloaded the keystatus property will become unavailable.
-r Recursively unloads the keys for the specified filesystem and all
descendent encryption roots.
-a Unloads the keys for all encryption roots in all imported pools.
zfs change-key [-l] [-o keylocation=value] [-o keyformat=value] [-o
pbkdf2iters=value] filesystem
zfs change-key -i [-l] filesystem
Changes the user's key (e.g. a passphrase) used to access a dataset.
This command requires that the existing key for the dataset is already
loaded. This command may also be used to change the keylocation,
keyformat, and pbkdf2iters properties as needed. If the dataset was
not previously an encryption root it will become one. Alternatively,
the -i flag may be provided to cause an encryption root to inherit the
does not overwrite the previous wrapped master key on disk, so it is
accessible via forensic analysis for an indeterminate length of time.
In the event of a master key compromise, ideally the drives should be
securely erased to remove all the old data (which is readable using the
compromised master key), a new pool created, and the data copied back.
This can be approximated in place by creating new datasets, copying the
data (e.g. using zfs send | zfs recv), and then clearing the free space
with zpool trim --secure if supported by your hardware, otherwise zpool
initialize.
-l Ensures the key is loaded before attempting to change the key.
This is effectively equivalent to running zfs load-key filesystem;
zfs change-key filesystem
-o property=value
Allows the user to set encryption key properties (keyformat,
keylocation, and pbkdf2iters) while changing the key. This is the
only way to alter keyformat and pbkdf2iters after the dataset has
been created.
-i Indicates that zfs should make filesystem inherit the key of its
parent. Note that this command can only be run on an encryption
root that has an encrypted parent.
Encryption
Enabling the encryption feature allows for the creation of encrypted
filesystems and volumes. ZFS will encrypt file and volume data, file
attributes, ACLs, permission bits, directory listings, FUID mappings, and
userused/groupused data. ZFS will not encrypt metadata related to the
pool structure, including dataset and snapshot names, dataset hierarchy,
properties, file size, file holes, and deduplication tables (though the
deduplicated data itself is encrypted).
Key rotation is managed by ZFS. Changing the user's key (e.g. a
passphrase) does not require re-encrypting the entire dataset. Datasets
can be scrubbed, resilvered, renamed, and deleted without the encryption
keys being loaded (see the load-key subcommand for more info on key
loading).
Creating an encrypted dataset requires specifying the encryption and
keyformat properties at creation time, along with an optional keylocation
and pbkdf2iters. After entering an encryption key, the created dataset
will become an encryption root. Any descendant datasets will inherit
their encryption key from the encryption root by default, meaning that
loading, unloading, or changing the key for the encryption root will
implicitly do the same for all inheriting datasets. If this inheritance
is not desired, simply supply a keyformat when creating the child dataset
or use zfs change-key to break an existing relationship, creating a new
encryption root on the child. Note that the child's keyformat may match
that of the parent while still creating a new encryption root, and that
changing the encryption property alone does not create a new encryption
root; this would simply use a different cipher suite with the same key as
its encryption root. The one exception is that clones will always use
their origin's encryption key. As a result of this exception, some
encryption-related properties (namely keystatus, keyformat, keylocation,
and pbkdf2iters) do not inherit like other ZFS properties and instead use
the value determined by their encryption root. Encryption root
inheritance can be tracked via the read-only encryptionroot property.
encryption enabled but for security, datasets will only deduplicate
against themselves, their snapshots, and their clones.
There are a few limitations on encrypted datasets. Encrypted data cannot
be embedded via the embedded_data feature. Encrypted datasets may not
have copies=3 since the implementation stores some encryption metadata
where the third copy would normally be. Since compression is applied
before encryption, datasets may be vulnerable to a CRIME-like attack if
applications accessing the data allow for it. Deduplication with
encryption will leak information about which blocks are equivalent in a
dataset and will incur an extra CPU cost for each block written.
SEE ALSO
zfsprops(7), zfs-create(8), zfs-set(8)
FreeBSD 14.0-RELEASE-p11 January 13, 2020 FreeBSD 14.0-RELEASE-p11