Before we talk about how to optimize or configure ANF volume performance, let’s review the storage hierarchy of ANF as below:
The above diagram shows the relationships of the Azure subscription, NetApp accounts, capacity pools, and volumes.
- A NetApp account serves as an administrative grouping of the constituent capacity pools.
- A NetApp account is not the same as your general Azure storage account.
- A NetApp account is regional in scope.
- You can have multiple NetApp accounts in a region, but each NetApp account is tied to only a single region.
Understanding how capacity pools work helps you select the right capacity pool types for your storage needs.
General rules of capacity pools
- A capacity pool is measured by its provisioned capacity.
See QoS types for additional information.
- The capacity is provisioned by the fixed SKUs that you purchased (for example, a 4-TiB capacity).
- A capacity pool can have only one service level.
- Each capacity pool can belong to only one NetApp account. However, you can have multiple capacity pools within a NetApp account.
- A capacity pool cannot be moved across NetApp accounts.
For example, in the Conceptual diagram of storage hierarchy below, Capacity Pool 1 cannot be moved from US East NetApp account to US West 2 NetApp account.
- A capacity pool cannot be deleted until all volumes within the capacity pool have been deleted.
Quality of Service (QoS) types for capacity pools/volumes
The QoS type is an attribute of a capacity pool. Azure NetApp Files provides two QoS types of capacity pools — auto (default) and manual.
Automatic (or auto) QoS type
When you create a capacity pool, the default QoS type is auto.
In an auto QoS capacity pool, throughput is assigned automatically to the volumes in the pool, proportional to the size quota assigned to the volumes.
The maximum throughput allocated to a volume depends on the service level of the capacity pool and the size quota of the volume. See Service levels for Azure NetApp Files for example calculation.
For performance considerations about QoS types, see Performance considerations for Azure NetApp Files.
Manual QoS type
When you create a capacity pool, you can specify for the capacity pool to use the manual QoS type. You can also change an existing capacity pool to use the manual QoS type. Setting the capacity type to manual QoS is a permanent change. You cannot convert a manual QoS type capacity tool to an auto QoS capacity pool.
In a manual QoS capacity pool, you can assign the capacity and throughput for a volume independently. For minimum and maximum throughput levels, see Resource limits for Azure NetApp Files. The total throughput of all volumes created with a manual QoS capacity pool is limited by the total throughput of the pool. It is determined by the combination of the pool size and the service-level throughput. For instance, a 4-TiB capacity pool with the Ultra service level has a total throughput capacity of 512 MiB/s (4 TiB x 128 MiB/s/TiB) available for the volumes.
If you are running your enterprise applications/file share where the actual data size is not large (e.g 500GB) but you want to assign higher bandwidth to this volume rather than automatically assign the throughput based on volume size, then manual QoS may be a better fit for your usage.