TrueNAS Early Release Documentation
This content follows TrueNAS 26 releases.
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Pool Creation Wizard Screen
24 minute read.
The Pool Creation Wizard configuration screens include a configuration preview and an inventory list of disks available on the system.
Create Pool at the top right of the Storage Dashboard screen opens the Pool Creation Wizard.
Configuration Preview lists pool and VDEV settings that dynamically update as you configure settings in the wizard.
Unassigned Disks shows the number of available disks by size on the system. This list dynamically updates as disks move to VDEVs added in the wizard.
The Pool Creation Wizard for most systems has seven configuration screens, numbered in sequence, to create a pool with VDEVs.
Larger iXsystems-provided servers for Enterprise users equipped with expansion shelves include the additional Enclosure Options screen.
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 the previous or next wizard 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.
The General Info shows the Name and Encryption options: None or Software Encryption ZFS, and shows available disks listed under Select disks you want to use. When available disks are exported from a pool, a message alerting you to this shows above the disk options.
| Setting | Description |
|---|---|
| Name | Sets the pool name, which can have up to 50 characters and must follow ZFS naming conventions. Names can have upper or lowercase alphanumeric characters, but use lower-case alpha characters to avoid potential problems with sharing protocols. Names can have special characters such as underscore (_), hyphen (-), colon (:), or a period (.), but do not begin a pool name with a special character. |
| Encryption | Shows two options: None and Software Encryption (ZFS). None does not apply encryption to the pool. Software Encryption (ZFS) applies ZFS encryption for the pool and all datasets (or zvols) within the pool created using the TrueNAS UI. Do not encrypt the root pool or the system dataset pool! All child datasets in an encrypted pool are encrypted and cannot be unencrypted. Best practice to allow the option for encrypted or unencrypted datasets in the pool is to create a new child dataset with encryption and leave the root dataset for the pool unencrypted. |
| Select disks you want to use | Shows disk options to select disk from, and if the options are disks from exported pools, a warning message shows just above the options. If system disks have non-unique serial numbers, a warning displays with additional fields. Allow non-unique serialed disks has two options, Allow and Don’t Allow. Allow permits using disks with non-unique serial numbers, such as those that can occur on virtual disks. The Data wizard screen shows the disks as available. Don’t Allow does not permit using disks with non-unique serial numbers. |
Encrypting the root dataset (pool-level encryption) creates a single point of failure. Losing one key makes the entire pool inaccessible.
Best practice Do not enable encryption during pool creation. Instead, create an unencrypted pool with individually encrypted datasets and zvols. This allows independent key management, selective unlock, isolated failures, and simplified recovery.
See Storage Encryption for more information on using TrueNAS storage encryption.
An encryption warning dialog opens with a Confirm option. Confirm enables the I Understand button. I Understand continues with adding the pool with encryption applied.
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.
Enterprise systems licensed for and containing SED encryption can use the Self Encryption Drives (SED) encryption type.
The General Info wizard screen shows the Self Encryption Drives (SED) radio button and options in addition to other General Info setting for non SED-licensed systems.
After selecting the Self Encryption Drives (SED) radio button, the Global SED Password and Confirm SED Password fields show.
The Global SED Password is a system-wide setting. A message shows above this field indicating if a password is already configured, and that entering a new password updates it for all pools using SED encryption.
The Enclosure Options wizard screen shows if the Enterprise system has one or more expansion shelves.
The three radio button options apply a dispersal strategy that sets the pool storage configuration topology. A dispersal strategy determines how the system adds disks by size and type to the pool VDEVs created when using the Automated Disk Selection option. Enclosures in the options below refer to the disk enclosures in the expansion shelves and system chassis.
No Enclosure Dispersal Strategy does not apply a dispersal strategy and does not show additional options. Disks added to the pool VDEVs are assigned in sequence based on disk availability, but are not balanced across all enclosures.
Maximum Dispersal Strategy applies a maximum dispersal strategy, which balances disk selection across all enclosures and available disks. Does not show additional options. Disks added to the pool VDEVs are spread across all available enclosure disks.
Limit Pool To A Single Enclosure applies a minimum dispersal strategy. Shows the Enclosure dropdown with a list of available expansion shelf options. Disks added to the pool VDEVs are spread across the enclosure disks that align with the selection in Enclosure.
The Data wizard screen shows options to automatically or manually add disks to a data VDEV. A pool must have a data VDEV before you can add other types of VDEVs to the pool.
Common Pool Creation Wizard Settings
The Layout dropdown list shows the Stripe, Mirror, RAIDZ1, RAIDZ2, RAIDZ3, dRAID1, dRAID2, and dRAID3 VDEV types.
This wizard screen lets you 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.
The Layouts field shows the following options:
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.
Mirror
Denotes that each disk in the VDEV stores an exact data copy. Requires at least two disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID
Each of these layouts has 1, 2, and 3 options. The options indicate the number of disks reserved for data parity and 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.
| 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. |
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 |
|---|---|
| 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 that dRAID layouts have data devices allocated in multiples of two. |
| 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. We recommend setting 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. |
The Log wizard screen settings configure a log VDEV. ZFS log devices can improve synchronous write speeds.
Common Pool Creation Wizard Settings
The Layout dropdown list includes the Stripe or Mirror types.
This wizard screen lets you 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.
The Layouts field shows the following options:
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.
Mirror
Denotes that each disk in the VDEV stores an exact data copy. Requires at least two disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID
Each of these layouts has 1, 2, and 3 options. The options indicate the number of disks reserved for data parity and 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.
| 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. |
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 |
|---|---|
| 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 that dRAID layouts have data devices allocated in multiples of two. |
| 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. We recommend setting 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. |
The Spare wizard screen settings configure a hot spare for a drive in a data VDEV.
Common Pool Creation Wizard Settings
This wizard screen lets you 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.
The Layouts field shows the following options:
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.
Mirror
Denotes that each disk in the VDEV stores an exact data copy. Requires at least two disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID
Each of these layouts has 1, 2, and 3 options. The options indicate the number of disks reserved for data parity and 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.
| 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. |
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 |
|---|---|
| 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 that dRAID layouts have data devices allocated in multiples of two. |
| 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. We recommend setting 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. |
The Cache wizard screen settings configure a ZFS L2ARC read-cache VDEV.
Common Pool Creation Wizard Settings
This wizard screen lets you 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.
The Layouts field shows the following options:
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.
Mirror
Denotes that each disk in the VDEV stores an exact data copy. Requires at least two disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID
Each of these layouts has 1, 2, and 3 options. The options indicate the number of disks reserved for data parity and 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.
| 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. |
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 |
|---|---|
| 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 that dRAID layouts have data devices allocated in multiples of two. |
| 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. We recommend setting 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. |
The Metadata wizard screen settings configure a special allocation class VDEV. Metadata VDEVS are used to speed up metadata and small block I/O. Use when creating a fusion pool.
Common Pool Creation Wizard Settings
The Layout dropdown list includes the Stripe or Mirror types.
This wizard screen lets you 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.
The Layouts field shows the following options:
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.
Mirror
Denotes that each disk in the VDEV stores an exact data copy. Requires at least two disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID
Each of these layouts has 1, 2, and 3 options. The options indicate the number of disks reserved for data parity and 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.
| 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. |
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 |
|---|---|
| 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 that dRAID layouts have data devices allocated in multiples of two. |
| 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. We recommend setting 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. |
The Dedup wizard screen settings configure a deduplication VDEV. A Dedup VDEV stores de-duplication tables. Size dedup VDEVs as x GiB for each x TiB of general storage.
Common Pool Creation Wizard Settings
The Layout dropdown list includes the Stripe or Mirror types.
This wizard screen lets you 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.
The Layouts field shows the following options:
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.
Mirror
Denotes that each disk in the VDEV stores an exact data copy. Requires at least two disks in the VDEV. Storage capacity is the size of a single disk in the VDEV.
RAIDZ and dRAID
Each of these layouts has 1, 2, and 3 options. The options indicate the number of disks reserved for data parity and 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.
| 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. |
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 |
|---|---|
| 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 that dRAID layouts have data devices allocated in multiples of two. |
| 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. We recommend setting 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. |
The Manual Selection screen shows settings to add a Data VDEV Layout and the individual disks available 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. The system dropdown list also shows a list of available system disks. Use the disk filters 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 listed to show only the selected type (HDD or SSD). |
| Filter by Disk Size | Resets the available disks listed 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 the disks displayed on this list. |
The Review wizard screen shows a summary of VDEVs in the pool 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.