QNAP

QTS 5.0.x

Creating a Block-Based LUN

  1. Go to one of the following screens.
    • iSCSI & Fibre Channel > iSCSI Storage

    • iSCSI & Fibre Channel > Fibre Channel > FC Storage

  2. Click Create, and then select New Block-Based LUN.

    The Block-Based LUN Creation Wizard opens.

  3. Select the storage pool that this LUN will be created in.
  4. Select a LUN allocation method.

    Allocation

    Description

    Thick instant allocation

    QTS allocates storage pool space when creating the LUN. This space is guaranteed to be available later.

    Thin provisioning

    QTS allocates storage pool space only when needed, such as when data is being written to the LUN. This ensures efficient use of space but there is no guarantee that space will be available.

  5. Click Next.
  6. Configure the following LUN settings.

    Setting

    Description

    LUN name

    • Length: 1 to 32 characters

    • Valid characters: 0-9, a-z, A-Z, underscore (_)

    LUN capacity

    Specify the maximum capacity of the LUN. The maximum capacity depends on the LUN allocation method:

    • Thick provisioning: Equal to the amount of free space in the parent storage pool.

    • Thin provisioning: 250 TB

    Tip:

    Select Maximum to allocate all remaining free space to the LUN.

  7. Optional: Configure any of the following advanced settings.

    Setting

    Description

    Sector size

    Changing the sector size to 4 KB increases LUN performance for specific applications and disk types.

    Important:

    VMware does not currently support a 4 KB sector size.

    Alert threshold

    QTS issues a warning notification when the percentage of used LUN space is equal to or above the specified threshold.

    Accelerate performance with SSD cache

    The SSD cache will be used to improve LUN access performance.

    Important:

    This setting is only available when the SSD cache is enabled.

    Report volatile write cache for data safety

    When enabled, QTS informs iSCSI initiators connected to this LUN that volatile write-cache is being used on the NAS. As a result, initiators might frequently tell QTS to flush cached LUN data to disk, which increases data safety but decreases LUN performance.

    FUA bit support

    When enabled, iSCSI initiators are able to tell QTS to flush important cached data to disk, instead of the whole read-write cache.

    Important:

    Both the iSCSI initiator and the application using the LUN must support this feature.

  8. Click Next.
  9. Optional: Deselect Do not map it to a target for now.

    If deselected, the Edit LUN Mapping wizard appears after QTS has finished creating the LUN.

  10. Click Finish.
  11. Optional: Map the LUN to an iSCSI target or Fibre Channel port group.