Examples of Encrypting ZFS File Systems

Example 5-1  Encrypting a ZFS File System by Using a Raw Key

In the following example, an aes-256-ccm encryption key is generated by using the pktool command and is written to a file, /cindykey.file.

# pktool genkey keystore=file outkey=/cindykey.file keytype=aes keylen=256

Then, the /cindykey.file is specified when the tank/home/cindy file system is created.

# zfs create -o encryption=aes-256-ccm -o keysource=raw,file:///cindykey.file
tank/home/cindy

Example 5-2  Encrypting a ZFS File System With a Different Encryption Algorithm

You can create a ZFS storage pool and have all the file systems in the storage pool inherit an encryption algorithm. In this example, the users pool is created and the users/home file system is created and encrypted by using a passphrase. The default encryption algorithm is aes-128-ccm.

Then, the users/home/mark file system is created and encrypted by using the aes-256-ccm encryption algorithm.

# zpool create -O encryption=on users mirror c0t1d0 c1t1d0 mirror c2t1d0 c3t1d0
Enter passphrase for 'users': xxxxxxxx
Enter again: xxxxxxxx
# zfs create users/home
# zfs get encryption users/home
NAME        PROPERTY    VALUE        SOURCE
users/home  encryption  on           inherited from users
# zfs create -o encryption=aes-256-ccm users/home/mark
# zfs get encryption users/home/mark
NAME               PROPERTY    VALUE        SOURCE
users/home/mark    encryption  aes-256-ccm  local

Example 5-3  Cloning an Encrypted ZFS File System

If the clone file system inherits the keysource property from the same file system as its origin snapshot, then a new keysource is not necessary, and you are not prompted for a new passphrase if keysource=passphrase,prompt. The same keysource is used for the clone. For example:

By default, you are not prompted for a key when cloning a descendent of an encrypted file system.

# zfs create -o encryption=on tank/ws
Enter passphrase for 'tank/ws': xxxxxxxx
Enter again: xxxxxxxx
# zfs create tank/ws/fs1
# zfs snapshot tank/ws/fs1@snap1
# zfs clone tank/ws/fs1@snap1 tank/ws/fs1clone

If you want to create a new key for the clone file system, use the zfs clone –K command.

If you clone an encrypted file system rather than a descendent encrypted file system, you are prompted to provide a new key. For example:

# zfs create -o encryption=on tank/ws
Enter passphrase for 'tank/ws': xxxxxxxx
Enter again: xxxxxxxx
# zfs snapshot tank/ws@1
# zfs clone tank/ws@1 tank/ws1clone
Enter passphrase for 'tank/ws1clone': xxxxxxxx
Enter again: xxxxxxxx

Example 5-4  Sending and Receiving an Encrypted ZFS File System

In the following example, the tank/home/darren@snap1 snapshot is created from the encrypted /tank/home/darren file system. Then, the snapshot is sent to bpool/snaps, with the encryption property enabled so the resulting received data is encrypted. However, the tank/home/darren@snap1 stream is not encrypted during the send process.

# zfs get encryption tank/home/darren
NAME              PROPERTY    VALUE        SOURCE
tank/home/darren  encryption  on           local
# zfs snapshot tank/home/darren@snap1
# zfs get encryption bpool/snaps
NAME         PROPERTY    VALUE        SOURCE
bpool/snaps  encryption  on           inherited from bpool
# zfs send tank/home/darren@snap1 | zfs receive bpool/snaps/darren1012
# zfs get encryption bpool/snaps/darren1012
NAME                    PROPERTY    VALUE        SOURCE
bpool/snaps/darren1012  encryption  on           inherited from bpool

In this case, a new key is automatically generated for the received encrypted file system.