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Storage Pool

With TNAS, you can integrate multiple disks into a unified storage device, called a storage pool. Based on this storage pool, you can easily create volumes. If there is available space in the storage pool, volumes can also be expanded. In addition, TNAS supports different types of RAID configurations, providing you with a variety of data protection levels.


Management and Operations​

Using the buttons in the feature configuration, you can perform the following operations:

  • Create: Create a storage pool.
  • Edit: Edit the remarks of the storage pool.
  • Delete: Delete a storage pool.
  • Settings: Set array synchronization speed and enable or disable RAID quick repair.
  • Array Repair: Repair a degraded array due to a faulty disk.
  • Add Disk: Add more disks to the array to increase the total capacity of the storage pool.
  • Array Migration: Migrate the array to a higher-level RAID mode.
  • Replace Disk: Replace disks in the array with larger capacity disks to increase the storage pool's total capacity; only one disk can be replaced at a time.
  • Data Cleanup: Helps maintain data integrity and improve storage space efficiency.
  • Mount:
     • In a Damaged Storage Pool, mounting reattaches disks from a degraded array and restores the pool to a usable state without rebooting.
     • In an Available Pool, mounting attaches a storage pool created on another device and restores it to a usable state without rebooting.

    • Note
    1. Before deleting a storage pool, all volumes within the pool must be deleted first.
    2. When a HyperLock-WORM volume exists in the storage pool, neither the HyperLock-WORM volume nor the storage pool can be deleted.
    3. Data cleanup is applicable for TRAID (non-single disk), TRAID+, RAID 1, RAID 5, RAID 6, and RAID 10.
    4. Data cleanup reduces storage performance, so it is recommended to run it during business idle hours.

    How to Change the RAID Type if I Don't Want to Use the Default TRAID?​

    Before Creating a Storage Pool:
    Go to Storage Manager > Storage Pool, click "Create Storage Pool", and select the desired RAID type from the drop-down menu.

    After Creating a Storage Pool:
    Change the RAID type via online array migration, or delete the current storage pool and recreate it.


    How to Perform Array Repair?​

    Applicable Situation: A disk failure in TNAS causes the array to degrade. TNAS emits a “beep” sound, a degraded array notification appears in TOS desktop messages, and the storage pool interface shows "Array Degraded".

    Applicable RAID Types: TRAID, TRAID+, RAID 1, RAID 5, RAID 6, RAID 10.

    Steps:

    1. Log in to TOS, go to Desktop > Messages, and identify the faulty disk.
    2. Go to Storage Manager > Storage Pool > More > Array Repair, and prepare a new disk that meets the type and capacity requirements to replace the faulty disk.
    3. Short-press the power button to turn off TNAS. After the power indicator turns off, remove the faulty disk and insert the new disk.
    4. Short-press the power button to turn on TNAS. Go to Storage Manager > Storage Pool > More > Array Repair > Select Disk > Confirm Settings, until array synchronization completes.


    How to Add Disks to an Array?​

    Applicable Situation: Increase the capacity of an existing array (storage pool) by adding disks without changing the RAID mode.

    Applicable RAID Types: TRAID, TRAID+, JBOD, RAID 5, RAID 6.

    Steps:

    1. Go to Storage Manager > Storage Pool > More > Add Disk, and prepare a new disk that meets the type and capacity requirements.
    2. Short-press the power button to turn off TNAS. After the power indicator turns off, insert the new disk.
    3. Short-press the power button to turn on TNAS. Go to Storage Manager > Storage Pool > More > Add Disk > Select Disk > Confirm Settings, until array synchronization completes.
    4. To add multiple disks, repeat steps 1-3 after synchronization completes.
    5. To allocate the added capacity to a volume, go to Storage Manager > Volume, click "Edit", and adjust the volume size as needed.


    How to Perform Online Array Migration?​

    Applicable Situation: Upgrade an existing array to a higher RAID level while retaining current data.
    Migration requires adding disks to TNAS and must follow the order: Single > RAID 1, RAID 1 > RAID 5, RAID 5 > RAID 6. Direct migration to RAID 10 is not supported; RAID 10 must be created during TOS array creation.

    Applicable RAID Types: TRAID, Single, RAID 1, RAID 5.

    TRAID to TRAID+ Migration:
    Refer to TRAID to TRAID+ Migration Guide

    Single, RAID 1, RAID 5 Migration Steps:

    1. Go to Storage Manager > Storage Pool > More > Array Migration, and prepare a new disk that meets the type and capacity requirements for migration.
    2. Short-press the power button to turn off TNAS. After the power indicator turns off, insert the new disk.
    3. Short-press the power button to turn on TNAS. Go to Storage Manager > Storage Pool > More > Array Migration > Select Disk > Confirm Settings, until array synchronization completes.
    4. To allocate the added capacity to a volume, go to Storage Manager > Volume, click "Edit", and adjust the volume size as needed.


    How to Replace Disks?​

    Applicable Situation: Replace smaller capacity disks with larger ones without changing the total number of disks, increasing available array capacity.

    Applicable RAID Types: TRAID, TRAID+, RAID 1, RAID 5, RAID 6.

    Steps:

    1. Go to Storage Manager > Storage Pool > More > Replace Disk, remove the disk to be replaced, and prepare a new disk that meets the type and capacity requirements.
    2. Short-press the power button to turn off TNAS. After the power indicator turns off, remove the old disk and insert the new disk.
    3. Short-press the power button to turn on TNAS. A continuous "beep" will sound; disable the buzzer via TOS desktop notification.
    4. Go to Storage Manager > Storage Pool (shows "Array Degraded") > More > Replace Disk > Select New Disk > Confirm Settings, until array synchronization completes.
    5. To replace multiple disks, repeat steps 1-4 after synchronization completes.
    6. To allocate the added capacity to a volume, go to Storage Manager > Volume, click "Edit", and adjust the volume size as needed.


    How to Mount a Damaged Storage Pool?​

    Applicable Situation: Storage pool is damaged due to missing required disks.

    Applicable RAID Types: All RAID types.

    Steps:

    1. Go to Storage Manager > Storage Pool (shows "Array Damaged") > Expand Details, and check required disks.
    2. Reinsert all required disks into TNAS.
    3. After the system detects all required disks, go to Storage Manager > Storage Pool > More > Mount > Confirm Settings to remount the storage pool.


    RAID Types​

    TRAID​

    TRAID (TerraMaster RAID) is an elastic disk array management tool developed by TerraMaster, offering automatic disk space combination, disk failure redundancy protection, and automatic expansion. These features require no manual configuration; the system automatically optimizes based on disk attributes. TRAID provides a flexible and optimized disk array management solution, ideal for new users unfamiliar with RAID setup. Learn more about TerraMaster TRAID

    Feature
    Description
    Advantage
    Has the benefits of RAID 5, with higher storage efficiency compared to RAID 5.
    Disadvantage
    Write performance is lower than RAID 0 and other non-parity RAID modes.
    Data Protection
    Can tolerate 1 disk failure (when array has two or more disks).
    Array Migration
    Can migrate to TRAID+
    Minimum Disks
    1
    Disk Capacity
    Optimized by system based on disk

    TRAID+​

    TRAID+ inherits all TRAID features and adds enhanced redundancy protection, allowing up to 2 disk failures, providing stronger data security.

    Feature
    Description
    Advantage
    Has the benefits of RAID 6, with higher storage efficiency compared to RAID 6.
    Disadvantage
    Write performance and storage efficiency lower than TRAID.
    Data Protection
    Can tolerate 2 disk failures.
    Array Migration
    Cannot migrate
    Minimum Disks
    4
    Disk Capacity
    Optimized by system based on disk

    Single​

    Single is the simplest storage configuration. The system uses a single disk directly for data storage without redundancy, striping, or combination functions.

    Feature
    Description
    Advantage
    High storage efficiency. The full capacity of the disk is usable with no waste. Low cost, as it involves only one disk.
    Disadvantage
    No redundancy, no read/write performance optimization.
    Data Protection
    If the disk fails, all data will be lost.
    Migration
    Can migrate to RAID 1.
    Minimum Number of Disks
    1 (only one disk can be used)
    Disk Capacity
    1 × (disk capacity)

    JBOD​

    JBOD combines multiple independent disks into one storage volume. Unlike RAID, JBOD provides no striping or redundancy.

    Feature
    Description
    Advantage
    High storage efficiency. The full capacity of all disks is usable with no waste.
    Disadvantage
    No redundancy, no improvement in read/write performance compared to a single disk.
    Data Protection
    Failure of one disk results in loss of the data stored on that disk.
    Migration
    Not supported
    Minimum Number of Disks
    2
    Disk Capacity
    Total capacity of all disks

    RAID 0​

    RAID 0 improves performance through striping, splitting data into blocks distributed across multiple disks.

    Feature
    Description
    Advantage
    Highest read/write performance among RAID levels. High storage efficiency with no capacity waste.
    Disadvantage
    Low reliability, no redundancy.
    Data Protection
    Failure of any disk results in total data loss for the entire RAID 0 array.
    Migration
    Not supported
    Minimum Number of Disks
    2
    Disk Capacity
    Total capacity of all disks

    RAID 1​

    RAID 1 is based on mirroring, duplicating data in real time to two or more disks. Each disk contains the same data, ensuring full recovery if one fails.

    Feature
    Description
    Advantage
    High data reliability, as all data is fully replicated across disks.
    Disadvantage
    Low storage efficiency, high cost.
    Data Protection
    As long as one disk remains functional, data is preserved.
    Migration
    Can migrate to RAID 5.
    Minimum Number of Disks
    2
    Disk Capacity
    Capacity of the smallest disk

    RAID 5​

    RAID 5 provides redundancy by striping data and distributing parity information across all disks. The parity allows recovery from a single disk failure.

    Feature
    Description
    Advantage
    High storage efficiency, good read performance, relatively low cost.
    Disadvantage
    Write performance is slower than RAID 0 and other parity-free modes due to parity calculation.
    Data Protection
    Can tolerate failure of 1 disk.
    Migration
    Can migrate to RAID 6.
    Minimum Number of Disks
    3
    Disk Capacity
    (N - 1) × (capacity of the smallest disk)

    RAID 6​

    RAID 6 uses dual parity, offering greater redundancy and fault tolerance.

    Feature
    Description
    Advantage
    Higher fault tolerance, good read performance.
    Disadvantage
    Lower write performance than RAID 5, reduced storage efficiency.
    Data Protection
    Can tolerate failure of 2 disks.
    Migration
    Not supported
    Minimum Number of Disks
    4
    Disk Capacity
    (N - 2) × (capacity of the smallest disk)

    RAID 10​

    RAID 10 combines RAID 1 (mirroring) and RAID 0 (striping), providing both redundancy and high performance.

    Feature
    Description
    Advantage
    High data security and excellent read/write performance. No parity calculation needed, write performance exceeds RAID 5 and RAID 6.
    Disadvantage
    Low storage efficiency, high cost.
    Data Protection
    If one disk in a mirrored pair fails, data remains available.
    Migration
    Not supported
    Minimum Number of Disks
    4 (total must be even)
    Disk Capacity
    (N / 2) × (capacity of the smallest disk)

    Note
    1. A new storage pool cannot be created until the previous synchronization is complete.
    2. To ensure stability and data safety, do not mix different types or sources (external vs. internal) of disks in one pool.
    3. Once an SSD is added to a storage pool, it cannot be configured as an SSD cache.
    4. It is recommended to use disks listed in the TNAS compatibility list. Unsupported disks may affect system stability or cause data loss.
    5. All existing data will be erased during storage pool creation. Ensure disks used do not contain important data.