Home > Storage > PowerScale (Isilon) > Product Documentation > Management and Migration > Storage Tiering with Dell PowerScale SmartPools > Data spillover
If a node pool fills up, writes to that pool automatically spill over to the next pool. This default behavior ensures that work can continue even if one type of capacity is full. In some circumstances, spillover is undesirable. For example, when different business units within an organization purchase separate pools or when data location has security or protection implications. In these circumstances, spillover can be disabled. Disabling spillover ensures that a file exists in one pool and will not move to another. Keep in mind that reservations for virtual hot sparing affect spillover. For example, if VHS is configured to reserve 10 percent of a pool’s capacity, spillover will occur at 90 percent full.
Protection settings can be configured outside SmartPools and managed at the cluster level, or within SmartPools at either the node pool or file pool level. Wherever protection levels exist, they are fully configurable and the default protection setting for a node pool is +2d:1n.