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:
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The RAID group must be one of the following RAID types: RAID 5, 6, 50, 60, TP.
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The RAID group must contain at least two SSDs that can provide estimated life remaining.
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At least one SSD in the RAID group must have over 3% estimated life remaining.
When QSAL is enabled, the following conditions apply:
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SSD over-provisioning is automatically enabled and set to 5% for the RAID group.
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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 |
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Enable QSAL for a new storage pool |
For details, see Creating a storage pool. |
Enable or disable QSAL for an existing storage pool |
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Monitor SSD life status in a QSAL-enabled RAID group |
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