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Dell Unity XT storage supports two types of storage pools on all-flash storage systems: traditional pools and dynamic pools. Traditional pools apply RAID protection to discrete groups of drives within the storage pool. Dynamic pools apply RAID to groups of drive extents from drives within the pool and allow for greater flexibility in managing and expanding the pool. Dynamic pools must be configured from all-flash drives; dynamic pools cannot be built with HDDs.
In general, it is recommended to use a single storage pool within Dell Unity XT arrays to reduce complexity and increase flexibility. However, it may be appropriate to configure additional storage pools in the following scenarios:
Additional information can be found in the Dell Unity XT: Dynamic Pools white paper.
Storage pool capacity is used for multiple purposes:
Storage pools must maintain free capacity to operate properly. By default, Dell Unity XT storage will raise an alert if a storage pool has less than 30% free capacity. Also, it will automatically invalidate snapshots and replication sessions if the storage pool has less than 5% free capacity. Dell Technologies recommends that a storage pool always has at least 10% free capacity.
All-flash pools provide the highest level of performance in Dell Unity XT storage. Use an all-flash pool when the application requires the highest storage performance at the lowest response time.
For example: For an all-flash pool, use only 1.6 TB SAS flash 3 drives and configure them all with RAID 5 8+1.
Hybrid pools are not applicable when using Dell Unity XT All-Flash arrays.