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How aggregate relocation works

Aggregate relocation takes advantage of the HA configuration to move the ownership of storage aggregates within the HA pair. Aggregate relocation enables storage management flexibility not only by optimizing performance during failover events, but also facilitating system operational and maintenance capabilities that previously required controller failover.

Aggregate relocation occurs automatically during manually initiated takeovers to reduce downtime during planned failover events such as nondisruptive software upgrades. You can manually initiate aggregate relocation independent of failover for performance load balancing, system maintenance, and nondisruptive controller upgrades. However, you cannot use the aggregate relocation operation to move ownership of the root aggregate.

The following illustration shows the relocation of the ownership of aggregate aggr_1 from Node1 to Node2 in the HA pair:

The aggregate relocation operation can relocate the ownership of one or more SFO aggregates if the destination node can support the number of volumes in the aggregates. There is only a brief interruption of access to each aggregate. Ownership information is changed one by one for the aggregates.

During takeover, aggregate relocation happens automatically after you manually initiate takeover. Before the target controller is taken over, ownership of each of the controller's aggregates is moved, one at a time, to the partner controller. When giveback is initiated, ownership is automatically moved back to the original node. The -bypass-optimization parameter can be used with the storage failover takeover command to suppress aggregate relocation during the takeover.

Aggregate relocation and Infinite Volumes with SnapDiff enabled

The aggregate relocation requires additional steps if the aggregate is currently used by an Infinite Volume with SnapDiff enabled. You must ensure that the destination node has a namespace mirror constituent, and make decisions about relocating aggregates that include namespace constituents.

For information about Infinite Volumes, see the Clustered Data ONTAP Infinite Volumes Management Guide.