Considerations when using thin provisioning with Infinite Volumes

You can use thin provisioning with an Infinite Volume, enabling you to allocate more storage to users than is physically available. Before using thin provisioning, you should understand what it is, where and when it is configured, and what its advantages and disadvantages are.

What thin provisioning is

With thin provisioning, the size of an Infinite Volume is not limited by the size of its associated aggregates. You can create a large volume on a small amount of storage, adding disks only as they are required. For example, you can create a 500 TB volume using aggregates that only have 250 TB of available space. The storage provided by the aggregates is used only as data is written. Thin provisioning is also called aggregate overcommitment.

The alternative of thin provisioning is thick provisioning, which allocates physical space immediately, regardless of whether that space is used for data yet. The allocated space cannot be used by any other volumes. When you use thick provisioning, all of the space required for the volume is allocated from the aggregate at the time of creating the volume.

Thin provisioning affects only the data constituents of an Infinite Volume. The namespace constituent and namespace mirror constituents of an Infinite Volume always use thick provisioning. For example, if you create a new Infinite Volume with a 10 TB namespace constituent and use thin provisioning, the namespace constituent will consume 10 TB of space even if the Infinite Volume does not contain any data.

When and where thin provisioning is configured

The way that you configure thin provisioning on an Infinite Volume depends on whether the Infinite Volume uses storage classes.

For an Infinite Volume without storage classes, thick and thin provisioning are configured at the volume level in the following way:

For an Infinite Volume with storage classes, thick and thin provisioning are configured at the storage-class level in the following way:

Advantages of thin provisioning

Using thin provisioning with Infinite Volumes provides the following advantages:

Disadvantages of thin provisioning

Thin provisioning includes the following disadvantages:

More information about thin provisioning

For more information about thin provisioning, see Thin Provisioning Deployment and Implementation Guide (TR-3965).