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QTS 5.0.x

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Expanding a Storage Pool by Adding a New RAID Group

The storage capacity of a storage pool can be expanded by creating a new RAID group and then adding it to the pool. This operation can be performed while the pool is online and accessible to users. QTS writes data linearly to storage pools containing multiple RAID groups. This means that QTS writes data to a RAID group until a group is full before writing data to the next RAID group.

  • If a storage pool contains multiple RAID groups and one RAID group fails, all data in the storage pool will be lost. Ensure that you have a complete data backup plan.

  • To expand a RAID 50 or RAID 60 pool, you must create a new RAID 50 or 60 group with the same number of disks and sub-groups as the original pool. It is not possible to add additional sub-groups.

  1. Go to Storage & Snapshots > Storage > Storage/Snapshots.
  2. Select a storage pool.
  3. Click Manage.

    The Storage Pool Management window opens.

  4. Select Action > Expand Pool.

    The Expand Storage Pool Wizard window opens.

  5. Select Create and add a new RAID group.
  6. Click Next.
  7. Optional: Select an expansion unit from the Enclosure Unit list.
    • You cannot select disks from multiple expansion units.

    • You cannot use the disks from a QNAP JBOD enclosure to expand a storage pool which is located on a different enclosure.

    • If the expansion unit is disconnected from the NAS, the storage pool becomes inaccessible until it is reconnected.

  8. Select one or more disks.

    If you select RAID 5, 6, 50, or 60 for the RAID type, you cannot select more than 16 disks.


    All data on the selected disks will be deleted.

  9. Select a RAID type.

    QTS displays all available RAID types and automatically selects the most optimized RAID type.

    • If the storage pool contains a RAID 1, RAID 5, RAID 6 or RAID 10 group, the new RAID group must also have one of the mentioned RAID types.

    • For RAID 50 or RAID 60, you cannot select a different RAID type.

  10. Optional: Select the disk that will be used as a hot spare for this RAID group.

    The designated hot spare automatically replaces any disk in the RAID group that fails.

  11. Click Next.
  12. Optional: Configure SSD over-provisioning.

    Over-provisioning reserves a percentage of SSD storage space on each disk in the RAID group to improve write performance and extend the disk's lifespan. You can decrease the amount of space reserved for over-provisioning after QTS has created the RAID group.


    To determine the optimal amount of over-provisioning for your SSDs, download and run SSD Profiling Tool from App Center.

  13. Click Next.
  14. Click Expand.

    A confirmation message appears.

  15. Click OK.

QTS creates the new RAID group and then starts rebuilding the storage pool. The capacity of the pool increases after RAID rebuilding is finished.