The auxiliary controls on extent attributes determine the following conditions:

• Whether allocations are aligned

  See Extent attribute alignment.

• Whether allocations are contiguous

  See Extent attribute contiguity.

• Whether the file can be written beyond its reservation

  See Write operations beyond extent attribute reservation.

• Whether an unused reservation is released when the file is closed

  See Extent attribute reservation trimming.

• Whether the reservation is a persistent attribute of the file

  See Extent attribute reservation persistence.

• When the space reserved for a file will actually become part of the file

  See Including an extent attribute reservation in the file.