What is the term for a zfs managed filesystem that is created from zfs pools?

There are two types of simple storage pools we can create. A striped pool , also called RAID-0 , in which the data is stored in “stripes” across all drives, or a mirrored pool , also called RAID-1 , in which a complete copy of all data is stored separately on each drive. Striped pools are not fault tolerant whereas mirrored pools can survive the failure of one drive. Striped pools have twice the storage capacity of mirrored pools and have better performance than mirrored pools.

To create a striped pool, we run:

sudo zpool create new-pool /dev/sdb /dev/sdc

To create a mirrored pool, we run:

sudo zpool create new-pool mirror /dev/sdb /dev/sdc

In both examples, new-pool is the name of the pool.

Sometimes an error like this might pop up:

A mirrored pool is usually recommended as we’d still be able to access our data if a single drive fails. However, this means that we’ll only get the capacity of a single drive. A striped pool, while giving us the combined storage of all drives, is rarely recommended as we’ll lose all our data if a drive fails. You can also opt for both, or change the designation at a later date if you add more drives to the pool.

The newly created pool is mounted at

sudo zpool create new-pool /dev/sdb /dev/sdc

sudo zpool create new-pool /dev/sdb /dev/sdc

ZFS on Linux version 0.8.0 introduced support for native encryption of datasets. After an upgrade from previous ZFS on Linux versions, the encryption feature can be enabled per pool:

# zpool get feature@encryption tank
NAME  PROPERTY            VALUE            SOURCE
tank  feature@encryption  disabled         local

# zpool set feature@encryption=enabled

# zpool get feature@encryption tank
NAME  PROPERTY            VALUE            SOURCE
tank  feature@encryption  enabled         local

There is currently no support for booting from pools with encrypted datasets using Grub, and only limited support for automatically unlocking encrypted datasets on boot. Older versions of ZFS without encryption support will not be able to decrypt stored data.

It is recommended to either unlock storage datasets manually after booting, or to write a custom unit to pass the key material needed for unlocking on boot to zfs load-key.

Establish and test a backup procedure before enabling encryption of production data. If the associated key material/passphrase/keyfile has been lost, accessing the encrypted data is no longer possible.

Encryption needs to be setup when creating datasets/zvols, and is inherited by default to child datasets. For example, to create an encrypted dataset tank/encrypted_data and configure it as storage in Proxmox VE, run the following commands:

# zfs create -o encryption=on -o keyformat=passphrase tank/encrypted_data
Enter passphrase:
Re-enter passphrase:

# pvesm add zfspool encrypted_zfs -pool tank/encrypted_data

All guest volumes/disks create on this storage will be encrypted with the shared key material of the parent dataset.

To actually use the storage, the associated key material needs to be loaded and the dataset needs to be mounted. This can be done in one step with:

# zfs mount -l tank/encrypted_data
Enter passphrase for 'tank/encrypted_data':

It is also possible to use a (random) keyfile instead of prompting for a passphrase by setting the keylocation and keyformat properties, either at creation time or with zfs change-key on existing datasets:

# dd if=/dev/urandom of=/path/to/keyfile bs=32 count=1

# zfs change-key -o keyformat=raw -o keylocation=file:///path/to/keyfile tank/encrypted_data

When using a keyfile, special care needs to be taken to secure the keyfile against unauthorized access or accidental loss. Without the keyfile, it is not possible to access the plaintext data!

A guest volume created underneath an encrypted dataset will have its encryptionroot property set accordingly. The key material only needs to be loaded once per encryptionroot to be available to all encrypted datasets underneath it.

See the encryptionroot, encryption, keylocation, keyformat and keystatus properties, the zfs load-key, zfs unload-key and zfs change-key commands and the Encryption section from man zfs for more details and advanced usage.

What is a ZFS pool?

What file under the proc directory contains information regarding what modules are currently loaded into the Linux kernel?

How does ZFS store data?

Which are typically loaded into the Linux kernel as a module select three?