Space Guarantee

Each flexible volume has a space guarantee attribute that controls how its storage is managed in relation to its containing aggregate. There are three possible settings for this attribute:

• volume—Data ONTAP pre-allocates space in the aggregate for the volume. The pre-allocated space cannot be allocated to any other volume in that aggregate.

  Space management for a flexible volume with space guarantee of volume is equivalent to a traditional volume or to all volumes in versions of Data ONTAP earlier than 7.0.

• file—Data ONTAP pre-allocates space in the volume so that any file in the volume with space reservation enabled can be completely rewritten, even if its blocks are pinned for a snapshot.

• none—Data ONTAP reserves no extra space for the volume. Writes to LUNs or files contained by that volume could fail if the containing aggregate does not have enough available space to accommodate the write.

Note: Because out-of-space errors are unexpected in a CIFS environment, do not set the space guarantee to none for volumes accessed using CIFS.

Space guarantees are honored only for online volumes. If you take a volume offline, any committed but unused space for that volume becomes available for other volumes in that aggregate. When you bring that volume back online, if there is not enough available space in the aggregate to fulfill its space guarantees, you must use the force (-f) option to disable the volume's space guarantees in order to bring the volume back online.

Note: Space guarantees are disabled for FlexClone volumes.

You can also use the space guarantee setting to pursue an aggregate overcommitment strategy.

For more information about space management issues, see the Data ONTAP Storage Management Guide.