A customer has a requirement for 450 TB of block storage to support their tier2...

To meet the customer's requirement for 450 TB of block storage with a 4:1 data reduction ratio, we need to calculate the effective usable capacity required and select the appropriate array configuration.

Step-by-Step Calculation:

Effective Usable Capacity Needed:

The workload requires450 TBof logical storage.

With a 4:1 data reduction ratio, the physical storage required is:

Array Selection:

The selected array must provide at least112.5 TBof usable capacity after accounting for overhead and RAID protection.

Let's evaluate the options:

A. FlashArray//C40R3 247 TB:

The FlashArray//C40R3 provides247 TBof raw capacity. After accounting for overhead (typically ~20%), the usable capacity is approximately:Usable Capacity=247TB×0.8=197.6TB.

This exceeds the required112.5 TB, making it a valid option.

B. FlashArray//C60R3 878 TB:

The FlashArray//C60R3 provides878 TBof raw capacity, which is significantly larger than needed. While it meets the requirement, it is not the minimum configuration.

C. FlashArray//X70R3 228 TB:

The FlashArray//X70R3 provides228 TBof raw capacity. After overhead, the usable capacity is approximately:Usable Capacity=228TB×0.8=182.4TB.

While this also meets the requirement, it is more expensive than the C40R3.

D. FlashArray//C60R3 366 TB:

The FlashArray//C60R3 with366 TBof raw capacity is overkill for this requirement and not cost-effective.

Recommendation:

TheFlashArray//C40R3 247 TBprovides the minimum required usable capacity while meeting the customer's needs.

Final Recommendation:

The correct answer isA. FlashArray//C40R3 247 TB.

References:

FlashArray//C Series Product Overview:

FlashArray//C Series

Details the capacity and use cases for FlashArray//C models.

Capacity Planning Guide:

Pure Storage Capacity Planning

Provides guidance on calculating usable capacity based on data reduction ratios.