Using thin provisioning, you can configure your volumes so that they appear to provide more storage than they have available, provided that the storage that is actually being used does not exceed the available storage.
To use thin provisioning with FlexVol volumes, you create the volume with a guarantee of none. With a guarantee of none, the volume size is not limited by the aggregate size. In fact, each volume could, if required, be larger than the containing aggregate. The storage provided by the aggregate is used up only as data is written to the LUN or file.
If the volumes associated with an aggregate show more storage as available than the physical resources available to that aggregate, the aggregate is overcommitted. When an aggregate is overcommitted, it is possible for writes to LUNs or files in volumes contained by that aggregate to fail if there is not sufficient free space available to accommodate the write.
If you have overcommitted your aggregate, you must monitor your available space and add storage to the aggregate as needed to avoid write errors due to insufficient space.
Aggregates can provide storage to FlexVol volumes associated with more than one Storage Virtual Machine (SVM). When sharing aggregates for thin-provisioned volumes in a multi-tenancy environment, be aware that one tenant's aggregate space availability can be adversely affected by the growth of another tenant's volumes.
For more information about thin provisioning, see the following technical reports: