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QNAP SSD Antiwear Leveling (QSAL)

QNAP SSD Antiwear Leveling (QSAL) is a patented QNAP technology that prevents simultaneous multiple SSD failure in a RAID group in a storage pool. It works by setting a different amount of over-provisioning on each SSD so that they wear at different rates.

To enable QSAL in a storage pool, the pool must contain a RAID group that meets the following requirements:

  • The RAID group must be one of the following RAID types: RAID 5, 6, 50, 60, TP.

  • The RAID group must contain at least two SSDs that can provide estimated life remaining.

  • At least one SSD in the RAID group must have over 3% estimated life remaining.

When QSAL is enabled, the following conditions apply:

  • SSD over-provisioning is automatically enabled and set to 5% for the RAID group.

  • The performance of the RAID group is reduced to that of an equivalent RAID group with one less disk.

You can enable QSAL for both new and existing storage pools. You can also monitor the life status of SSDs in a QSAL-enabled RAID group.

Action

User Action

Enable QSAL for a new storage pool

For details, see Creating a storage pool.

Enable or disable QSAL for an existing storage pool

  1. Go to Storage & Snapshots > Storage > Storage/Snapshots.

  2. Select a storage pool.

  3. Click Manage.

    The Storage Pool Management window opens.

  4. Click QSAL.

    Note:

    This screen is only available if the storage pool contains a RAID group that meets the requirements.

  5. Click the toggle button.

Monitor SSD life status in a QSAL-enabled RAID group

  1. Go to Storage & Snapshots > Storage > Storage/Snapshots.

  2. Select a storage pool containing a QSAL-enabled RAID group.

  3. Click Manage.

    The Storage Pool Management window opens.

  4. Click QSAL.

  5. Select a RAID group.

    Storage & Snapshots displays QSAL information on the RAID group.

    On this screen, you can monitor the estimated remaining life of SSDs, replace an SSD with a spare disk, or configure a spare disk.