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Working with Flash Pool aggregates

You configure a Flash Pool aggregate by adding SSD RAID groups to an existing HDD aggregate. The SSD RAID groups can be composed of physical SSDs or allocation units from SSD storage pools.

  • Flash Pool caching policies and SSD partitioning
    Caching policies for the volumes in a Flash Pool aggregate let you deploy flash as high performance cache for your working data set while using lower-cost HDDs for less frequently accessed data. If you are providing cache to two or more Flash Pool aggregates, you should use Flash Pool SSD partitioning to share SSDs across the aggregates in the Flash Pool.
  • Determining Flash Pool candidacy and optimal cache size
    Before converting an existing aggregate to a Flash Pool aggregate, you can determine whether the aggregate is I/O bound, and what would be the best Flash Pool cache size for your workload and budget. You can also check whether the cache of an existing Flash Pool aggregate is sized correctly.
  • Creating a Flash Pool aggregate using physical SSDs
    You create a Flash Pool aggregate by enabling the feature on an existing aggregate composed of HDD RAID groups, and then adding one or more SSD RAID groups to that aggregate. This results in two sets of RAID groups for that aggregate: SSD RAID groups (the SSD cache) and HDD RAID groups.
  • Creating a Flash Pool aggregate using SSD storage pools
    You can configure a Flash Pool aggregate by adding one or more allocation units from an SSD storage pool to an existing HDD aggregate.
  • Determining whether to modify the caching policy of Flash Pool aggregates
    You can assign cache-retention policies to volumes in Flash Pool aggregates to determine how long the volume data remains in the Flash Pool cache. However, in some cases changing the cache-retention policy might not impact the amount of time the volume's data remains in the cache.