Creating a local tier (aggregate) estimates usable size approximately 5% less than actual created size
Applies to
- ONTAP 9.12.1+ with AFF Platforms
- ONTAP 9.14.1+ with FAS Platforms
- 30TiB or larger aggregates
- Using either the Add local tiers automatically (create aggregates with auto-provisioning) or Add local tiers (create aggregates) manually process
Issue
- When creating a local tier (aggregate) ONTAP reports a Usable Size approximately 5% smaller than the actual Size of the aggregate once created:
cluster1::> storage aggregate auto-provision -nodes cluster1-01 -verbose true
Per node summary of new aggregates to create, discovered spares, and also
remaining spare disks and partitions after aggregate creation:
New Total New Discovered Spare Remaining Spare
Node Aggrs Usable Size Disks Partitions Disks Partitions
------------------ ----- ------------ ------ ----------- ------ ----------
cluster1-01 1 50.00TB 42 0 2 0
cluster1::> storage aggregate show -fields size -aggregate cluster1_01_SAS_1
aggregate size
-------------------- -------
cluster1_01_SAS_1 52.78TB
- As detailed in the ONTAP® 9 Release Notes the following enhancements were made:
- For All Flash FAS (AFF) and the FAS500f platforms, the WAFL reserve for aggregates greater than 30TB is reduced from 10% to 5%, resulting in increased usable space in the aggregate. Available beginning ONTAP 9.12.1.
- For FAS platforms, the WAFL reserve for aggregates greater than 30TB in size is reduced from 10% to 5%, resulting in increased usable space in the aggregate. Available beginning ONTAP 9.14.1.