Recommended volume and file or LUN configuration combinations overview

Contributors

There are specific combinations of FlexVol volume and file or LUN configurations you can use, depending on your application and administration requirements. Understanding the benefits and costs of these combinations can help you determine the right volume and LUN configuration combination for your environment.

The following volume and LUN configuration combinations are recommended:

  • Space-reserved files or LUNs with thick volume provisioning

  • Non-space-reserved files or LUNs with thin volume provisioning

  • Space-reserved files or LUNs with semi-thick volume provisioning

You can use SCSI thin provisioning on your LUNs in conjunction with any of these configuration combinations.

Space-reserved files or LUNs with thick volume provisioning

Benefits:

  • All write operations within space-reserved files are guaranteed; they will not fail due to insufficient space.

  • There are no restrictions on storage efficiency and data protection technologies on the volume.

Costs and limitations:

  • Enough space must be set aside from the aggregate up front to support the thickly provisioned volume.

  • Space equal to twice the size of the LUN is allocated from the volume at LUN creation time.

Non-space-reserved files or LUNs with thin volume provisioning

Benefits:

  • There are no restrictions on storage efficiency and data protection technologies on the volume.

  • Space is allocated only as it is used.

Costs and restrictions:

  • Write operations are not guaranteed; they can fail if the volume runs out of free space.

  • You must manage the free space in the aggregate effectively to prevent the aggregate from running out of free space.

Space-reserved files or LUNs with semi-thick volume provisioning

Benefits:

Less space is reserved up front than for thick volume provisioning, and a best-effort write guarantee is still provided.

Costs and restrictions:

  • Write operations can fail with this option.

    You can mitigate this risk by properly balancing free space in the volume against data volatility.

  • You cannot rely on retention of data protection objects such as Snapshot copies and FlexClone files and LUNs.

  • You cannot use ONTAP block-sharing storage efficiency capabilities that cannot be automatically deleted, including deduplication, compression, and ODX/Copy Offload.