The value 77.24 T in the context of Pure Storage FlashArray represents C. The guaranteed capacity.
Guaranteed Capacity is a feature of Pure Storage’s Evergreen subscription model. It reflects the effective capacity Pure Storage commits to the customer based on their typical data reduction ratios (deduplication, compression, and pattern removal). This value is calculated as:
Guaranteed Capacity=Physical Raw Capacity×Data Reduction Factor (DRF)Guaranteed Capacity=Physical Raw Capacity×Data Reduction Factor (DRF)
Pure typically guarantees a minimum DRF (e.g., 3:1 for many workloads), but actual savings often exceed this.
Why Not the Other Options?
A. Total usable space: This would include the total logical capacity after data reduction and overheads (RAID-HD, metadata), which is usually larger than the guaranteed capacity.
B. Total raw space: This refers to the physical capacity of drives (e.g., 100TB raw). The value shown (77.24T) is smaller than raw, so this is incorrect.
D. Total deduplicated space: Pure Storage combines dedupe, compression, and pattern removal into a single "data reduction" metric. Deduplication alone is not isolated in capacity reporting.
Official Reference:
Pure Storage documentation explicitly defines Guaranteed Capacity as the "logical capacity Pure commits to deliver, factoring in data reduction." This aligns with the Evergreen//Forever subscription model, where customers pay for usable capacity, not raw storage.
