Table of ContentsView in Frames

Volume space guarantees and aggregate overcommitment

You can use aggregate overcommitment to advertise more available space than the available space.

When managing storage resources, it is important to understand the role of aggregate overcommitment in space availability. To use aggregate overcommitment, you must create flexible volumes with a space guarantee of none or file so that the aggregate size does not limit the volume size. Each volume can be larger than its containing aggregate. You can use the storage space that the aggregate provides, as required, by creating LUNs, or adding data to volumes.

By using aggregate overcommitment, the storage system can advertise more available storage than actually exists in the aggregate. With aggregate overcommitment, you can provide greater amounts of storage that you know would be used immediately. Alternatively, if you have several volumes that sometimes need to grow temporarily, the volumes can dynamically share the available space with each other.

Note: If you have overcommitted your aggregate, you must monitor its available space carefully and add storage as required to avoid write errors due to insufficient space.

For details about volume space reservations and aggregate overcommitment, see the Data ONTAP Storage Management Guide for 7-Mode.