Pool Creation Wizard

23 minute read.

Last Modified 2024-03-19 08:38 EDT

The Pool Creation Wizard includes the wizard configuration screens, a configuration preview, and an inventory list of disks available on the system.

The Create Pool button at the top right of the Storage Dashboard screen opens the Pool Creation Wizard.

The Configuration Preview displays a list of Pool and VDEV settings that dynamically update as you configure settings in the wizard.

The Inventory area displays the number of available disks by size on the system. This list dynamically updates as disks move to VDEVs added in the wizard.

Pool Creation Wizard

The Pool Creation Wizard has seven configuration screens, numbered in sequence, to create a pool with VDEVs.

Each wizard VDEV configuration screen includes the Automated Disk Selection and Advanced Options areas. Click Manual Disk Selection to open the Manual Selection screen.

Back and Next move to either the previous or next wizard configuration screen. Reset Step clears the VDEV settings for the VDEV type selected. For example, Data VDEV configuration. Save And Go To Review saves the current selections and goes directly to the Review wizard screen.

General Info

The General Info screen includes two default settings, Name and Encryption.

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Name is a required field. Enter a name for the pool of up to 50 characters in length that follows ZFS naming conventions. Use lower-case alpha characters to avoid potential problems with sharing protocols. Names can include numbers and special characters such as underscore (_), hyphen (-), colon (:), or a period (.).

Encryption applies key type encryption to the pool. Select to enable ZFS encryption for this pool and all datasets (or zvols) created within the pool. See Storage Encryption for more information on using SCALE storage encryption. An encryption warning dialog displays with a Confirm checkbox. Select to enable the I Understand button. I Understand allows you to continue adding the pool with encryption applied.

Applying encryption at the pool level also encrypts all datasets (and zvols) within the pool.
Keep the encryption key file in a safe location where you perform regular backups. Losing the encryption key file results in lost data you cannot recover.

If system disks have data exported from pools on them, a warning displays with a checkbox for the pool name.

General Info With Exported Pools — Figure 3: General Info with Exported Pools

If system disks have non-unique serial numbers, a warning displays with additional fields.

Figure 4: Non-Unique Serial Numbers Screen

Allow non-unique serialed disks has two radio buttons, Allow and Don’t Allow.

Allow permits using disks with non-unique serial numbers, such as those that can occur on virtual disks, and displays them as available disks on the Data wizard screen. Don’t Allow does not permit using disks with non-unique serial numbers.

Data

The Data wizard screen provides the option to automatically or manually add disks to the data VDEV. You must add a data VDEV before adding other types of VDEVs to the pool.

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Layout displays a dropdown list of VDEV layouts (Stripe, Mirror, RAIDZ1, RAIDZ2, RAIDZ3, dRAID1, dRAID2, dRAID3).

This wizard screen provides the option to configure a VDEV using the Automated Disk Selection fields. To individually find and select disks for a VDEV, click Manual Disk Selection in the Advanced Options area.

Choosing a dRAID VDEV layout removes the Manual Disk Selection button and adds different options to the Automated Disk Selection area. It also removes the Spare VDEV section from the pool creation wizard and replaces it with the Distributed Hot Spares option in the Data VDEV section.

VDEV Layouts

A Stripe designates that each disk is used sequentially in the VDEV. Requires at least one disk and has no redundancy. A data VDEV with a stripe layout irretrievably loses all stored data if a single disk in the VDEV fails. Not recommended for data VDEVs storing critical data.
A Mirror denotes that each disk in the VDEV stores an exact data copy. Requires at least 2 disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID layouts each have 1, 2, and 3 options. These indicate the number of disks reserved for data parity and also the number of disks that can fail in the VDEV without data loss to the pool. For example, a RAIDZ2 layout reserves two additional disks for parity and two disks can fail without data loss.

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Width	Select the number of disks from the options provided on the dropdown list.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list.

Automated Disk Selection - dRAID layouts

Similar to RAIDZ, dRAID layout numbers (1, 2, or 3) indicate the parity level and how many disks can fail without data loss to the pool.

TrueNAS defaults to allocating 10 disks minimum as dRAID VDEV in Children. If creating a data VDEV with fewer than 10 disks, using a RAIDZ layout is strongly recommended for better performance and capacity optimization.

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Data Devices	Data stripe width for the VDEV. Select the number of disks from the options provided on the dropdown list. TrueNAS recommends dRAID layouts have data devices allocated in multiples of 2.
Distributed Hot Spares	Number of disk areas to actively provide spare capacity to the entire VDEV. These areas are active within the pool and function in of adding a Spare VDEV to the pool. It is recommended to set this to at least 1. The Distributed Hot Spares number cannot be modified after the pool is created.
Children	The total number of disks to allocate in the dRAID VDEV. The field selection and options update dynamically based on the chosen dRAID Layout, Disk Size, Data Devices, and Distributed Hot Spares. Increasing the number of Children in the dRAID VDEV can reduce the options for Number of VDEVs.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list. Options are populated dynamically depending on the selections made in all the other fields.

Log (Optional)

The wizard Log screen provides the option to configure a log VDEV. ZFS log devices can improve speeds of synchronous writes.

Figure 6: Pool Creation Wizard Log Screen

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Layout displays a dropdown list of VDEV layouts (Stripe or Mirror).

VDEV Layouts

A Stripe designates that each disk is used sequentially in the VDEV. Requires at least one disk and has no redundancy. A data VDEV with a stripe layout irretrievably loses all stored data if a single disk in the VDEV fails. Not recommended for data VDEVs storing critical data.
A Mirror denotes that each disk in the VDEV stores an exact data copy. Requires at least 2 disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID layouts each have 1, 2, and 3 options. These indicate the number of disks reserved for data parity and also the number of disks that can fail in the VDEV without data loss to the pool. For example, a RAIDZ2 layout reserves two additional disks for parity and two disks can fail without data loss.

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Width	Select the number of disks from the options provided on the dropdown list.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list.

Automated Disk Selection - dRAID layouts

Similar to RAIDZ, dRAID layout numbers (1, 2, or 3) indicate the parity level and how many disks can fail without data loss to the pool.

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Data Devices	Data stripe width for the VDEV. Select the number of disks from the options provided on the dropdown list. TrueNAS recommends dRAID layouts have data devices allocated in multiples of 2.
Distributed Hot Spares	Number of disk areas to actively provide spare capacity to the entire VDEV. These areas are active within the pool and function in of adding a Spare VDEV to the pool. It is recommended to set this to at least 1. The Distributed Hot Spares number cannot be modified after the pool is created.
Children	The total number of disks to allocate in the dRAID VDEV. The field selection and options update dynamically based on the chosen dRAID Layout, Disk Size, Data Devices, and Distributed Hot Spares. Increasing the number of Children in the dRAID VDEV can reduce the options for Number of VDEVs.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list. Options are populated dynamically depending on the selections made in all the other fields.

Spare (Optional)

The Spare wizard screen provides the option to configure a hot spare for a drive in a data VDEV.

Figure 7: Pool Creation Wizard Spare Screen

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VDEV Layouts

A Stripe designates that each disk is used sequentially in the VDEV. Requires at least one disk and has no redundancy. A data VDEV with a stripe layout irretrievably loses all stored data if a single disk in the VDEV fails. Not recommended for data VDEVs storing critical data.
A Mirror denotes that each disk in the VDEV stores an exact data copy. Requires at least 2 disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID layouts each have 1, 2, and 3 options. These indicate the number of disks reserved for data parity and also the number of disks that can fail in the VDEV without data loss to the pool. For example, a RAIDZ2 layout reserves two additional disks for parity and two disks can fail without data loss.

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Width	Select the number of disks from the options provided on the dropdown list.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list.

Automated Disk Selection - dRAID layouts

Similar to RAIDZ, dRAID layout numbers (1, 2, or 3) indicate the parity level and how many disks can fail without data loss to the pool.

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Data Devices	Data stripe width for the VDEV. Select the number of disks from the options provided on the dropdown list. TrueNAS recommends dRAID layouts have data devices allocated in multiples of 2.
Distributed Hot Spares	Number of disk areas to actively provide spare capacity to the entire VDEV. These areas are active within the pool and function in of adding a Spare VDEV to the pool. It is recommended to set this to at least 1. The Distributed Hot Spares number cannot be modified after the pool is created.
Children	The total number of disks to allocate in the dRAID VDEV. The field selection and options update dynamically based on the chosen dRAID Layout, Disk Size, Data Devices, and Distributed Hot Spares. Increasing the number of Children in the dRAID VDEV can reduce the options for Number of VDEVs.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list. Options are populated dynamically depending on the selections made in all the other fields.

Cache (Optional)

The Cache wizard screen provides the option to configure a ZFS L2ARC read-cache VDEV.

Figure 8: Pool Creation Wizard Cache Screen

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VDEV Layouts

A Stripe designates that each disk is used sequentially in the VDEV. Requires at least one disk and has no redundancy. A data VDEV with a stripe layout irretrievably loses all stored data if a single disk in the VDEV fails. Not recommended for data VDEVs storing critical data.
A Mirror denotes that each disk in the VDEV stores an exact data copy. Requires at least 2 disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID layouts each have 1, 2, and 3 options. These indicate the number of disks reserved for data parity and also the number of disks that can fail in the VDEV without data loss to the pool. For example, a RAIDZ2 layout reserves two additional disks for parity and two disks can fail without data loss.

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Width	Select the number of disks from the options provided on the dropdown list.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list.

Automated Disk Selection - dRAID layouts

Similar to RAIDZ, dRAID layout numbers (1, 2, or 3) indicate the parity level and how many disks can fail without data loss to the pool.

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Data Devices	Data stripe width for the VDEV. Select the number of disks from the options provided on the dropdown list. TrueNAS recommends dRAID layouts have data devices allocated in multiples of 2.
Distributed Hot Spares	Number of disk areas to actively provide spare capacity to the entire VDEV. These areas are active within the pool and function in of adding a Spare VDEV to the pool. It is recommended to set this to at least 1. The Distributed Hot Spares number cannot be modified after the pool is created.
Children	The total number of disks to allocate in the dRAID VDEV. The field selection and options update dynamically based on the chosen dRAID Layout, Disk Size, Data Devices, and Distributed Hot Spares. Increasing the number of Children in the dRAID VDEV can reduce the options for Number of VDEVs.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list. Options are populated dynamically depending on the selections made in all the other fields.

Metadata (Optional)

The Metadata wizard screen provides the option to configure a special allocation class VDEV, for use when creating a fusion pool. This VDEV type is used to speed up metadata and small block IO.

Figure 9: Pool Creation Wizard Metadata Screen

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VDEV Layouts

A Stripe designates that each disk is used sequentially in the VDEV. Requires at least one disk and has no redundancy. A data VDEV with a stripe layout irretrievably loses all stored data if a single disk in the VDEV fails. Not recommended for data VDEVs storing critical data.
A Mirror denotes that each disk in the VDEV stores an exact data copy. Requires at least 2 disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID layouts each have 1, 2, and 3 options. These indicate the number of disks reserved for data parity and also the number of disks that can fail in the VDEV without data loss to the pool. For example, a RAIDZ2 layout reserves two additional disks for parity and two disks can fail without data loss.

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Width	Select the number of disks from the options provided on the dropdown list.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list.

Automated Disk Selection - dRAID layouts

Similar to RAIDZ, dRAID layout numbers (1, 2, or 3) indicate the parity level and how many disks can fail without data loss to the pool.

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Data Devices	Data stripe width for the VDEV. Select the number of disks from the options provided on the dropdown list. TrueNAS recommends dRAID layouts have data devices allocated in multiples of 2.
Distributed Hot Spares	Number of disk areas to actively provide spare capacity to the entire VDEV. These areas are active within the pool and function in of adding a Spare VDEV to the pool. It is recommended to set this to at least 1. The Distributed Hot Spares number cannot be modified after the pool is created.
Children	The total number of disks to allocate in the dRAID VDEV. The field selection and options update dynamically based on the chosen dRAID Layout, Disk Size, Data Devices, and Distributed Hot Spares. Increasing the number of Children in the dRAID VDEV can reduce the options for Number of VDEVs.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list. Options are populated dynamically depending on the selections made in all the other fields.

Dedup (Optional)

The Dedup wizard screen provides the option to configure a VDEV to use for storing de-duplication tables. Size dedup VDEVs as x GiB for each x TiB of general storage.

Figure 10: Pool Creation Wizard Dedup Screen

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VDEV Layouts

A Stripe designates that each disk is used sequentially in the VDEV. Requires at least one disk and has no redundancy. A data VDEV with a stripe layout irretrievably loses all stored data if a single disk in the VDEV fails. Not recommended for data VDEVs storing critical data.
A Mirror denotes that each disk in the VDEV stores an exact data copy. Requires at least 2 disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID layouts each have 1, 2, and 3 options. These indicate the number of disks reserved for data parity and also the number of disks that can fail in the VDEV without data loss to the pool. For example, a RAIDZ2 layout reserves two additional disks for parity and two disks can fail without data loss.

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Width	Select the number of disks from the options provided on the dropdown list.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list.

Automated Disk Selection - dRAID layouts

Similar to RAIDZ, dRAID layout numbers (1, 2, or 3) indicate the parity level and how many disks can fail without data loss to the pool.

Setting	Description
Disk Size	Select the disk size from the list that displays. The list shows disks by size in GiB and type (SSD or HDD).
Treat Disk Size as Minimum	Select to use disks of the size selected in Disk Size or larger. If not selected, only disks of the size selected in Disk Size are used.
Data Devices	Data stripe width for the VDEV. Select the number of disks from the options provided on the dropdown list. TrueNAS recommends dRAID layouts have data devices allocated in multiples of 2.
Distributed Hot Spares	Number of disk areas to actively provide spare capacity to the entire VDEV. These areas are active within the pool and function in of adding a Spare VDEV to the pool. It is recommended to set this to at least 1. The Distributed Hot Spares number cannot be modified after the pool is created.
Children	The total number of disks to allocate in the dRAID VDEV. The field selection and options update dynamically based on the chosen dRAID Layout, Disk Size, Data Devices, and Distributed Hot Spares. Increasing the number of Children in the dRAID VDEV can reduce the options for Number of VDEVs.
Number of VDEVs	Select the number of VDEVs from the options provided on the dropdown list. Options are populated dynamically depending on the selections made in all the other fields.

Advanced Options

The Manual Selection screen allows adding a Stripe or the Data VDEV Layout and then selecting individual disks to add to the new VDEV. You can filter disks by type or size.

Add places a VDEV area to populate with individual disks.

The screen shows disk icons for available disks, or click on the system field to expand the dropdown list to show a list of available system disks. The disk filters can be used separately or together to find disks of the same type and size. Drag disks to the VDEV to add them.

Save Selection creates the VDEV and closes the window.

Setting	Description
Search	Enter the disk name or other details to search for disks matching the specified value to filter available disks in the system.
Filter by Disk Type	Resets the available disks list to show only the selected type (HDD or SSD).
Filter by Disk Size	Resets the available disks list to show only disks matching the selected size.
TrueNAS System	Click to expand and show the list of available disks in the system. Filter options change disks displayed on this list.

Review

The Review wizard screen displays a summary of the pool VDEV configuration.

Inspect VDEVs opens the Inspect VDEVs screen that shows the VDEVs with assigned disks added to the pool.

Start Over clears the current pool configuration so you can start over.

Create Pool completes the configuration process and adds the pool.

Use Cases

Industry

Support

Resources

Pool Creation Wizard

Pool Creation Wizard

General Info

Data

VDEV Layouts

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Automated Disk Selection - dRAID layouts

Log (Optional)

VDEV Layouts

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Automated Disk Selection - dRAID layouts

Spare (Optional)

VDEV Layouts

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Automated Disk Selection - dRAID layouts

Cache (Optional)

VDEV Layouts

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Automated Disk Selection - dRAID layouts

Metadata (Optional)

VDEV Layouts

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Automated Disk Selection - dRAID layouts

Dedup (Optional)

VDEV Layouts

Automated Disk Selection - Stripe, Mirror, and RAIDZ layouts

Automated Disk Selection - dRAID layouts

Advanced Options

Review

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