Table of ContentsView in Frames

Estimated usable capacity of an aggregate

When you use System Manager to create an aggregate or increase capacity of an aggregate, the estimated usable capacity is calculated by excluding 10% reserved capacity for WAFL from the total usable capacity of the data disks. Understanding the estimated usable capacity helps you while provisioning storage to aggregates.

The estimated usable capacity is lesser than the total usable capacity of the data disks because 10% of the space is reserved for WAFL. For example, if 5 disks each of size 1 TB are used to create a RAID-DP aggregate, then the estimated usable capacity displayed is 2.7 TB. This is because 2 TB is assigned for RAID-DP parity, and from the remaining 3 TB assigned as data disks, 10% (0.3 TB) is reserved for WAFL.