If reallocation has been enabled on your storage system, you can initiate an aggregate reallocation scan to optimize the location of physical blocks in the aggregate, thus increasing contiguous free space in the aggregate.
An aggregate reallocation scan reallocates free space and is not the same as file reallocation. In particular, after adding new disks to an aggregate, if you want to ensure that blocks are laid out sequentially throughout the aggregate, you should use reallocate start -f on each volume instead of reallocate start -A on the aggregate.
Because blocks in an aggregate Snapshot copy will not be reallocated, consider deleting aggregate Snapshot copies before performing aggregate reallocation to allow the reallocation to perform better.