An Implementation Engineer is planning to add a DirectFlash Shelf to a FlashArray//XL with an existing DirectFlash Shelf. Which PCIe slot must be…

The Pure Storage FlashArray//XL has a specific and mandatory PCIe slot assignment for connecting DirectFlash Shelves (DFS). The Host Bus Adapter (HBA) for the first DFS must be installed in PCIe slot 4. For expansion with a second DFS, the HBA must be installed in PCIe slot 6. Since the scenario describes adding a second shelf to an array that already has one, the engineer must use slot 6 for the new HBA to ensure proper connectivity, performance, and adherence to the supported hardware configuration.

A. 0: PCIe slot 0 in a FlashArray//XL controller is reserved for the quad-port 10/25GbE card used for management and replication, not for DirectFlash Shelf connectivity.

B. 4: PCIe slot 4 is the mandatory location for the HBA connecting the first DirectFlash Shelf. This slot is already occupied in the described scenario.

1. Pure Storage, Inc. (2023). FlashArray//X and //XL Installation and Upgrade Guide Purity 6.x. Section: "PCIe Card Slot Configurations for FlashArray//XL", Page 41. The guide explicitly states: "The first DirectFlash Shelf HBA must be installed in PCIe slot 4. The second DirectFlash Shelf HBA must be installed in PCIe slot 6."

2. Pure Storage, Inc. (2023). FlashArray Hardware Guide. Document ID: 35-0001-01-REV-L. Section: "FlashArray//XL Chassis", Page 28. The chassis diagram and accompanying tables detail the specific functions assigned to each PCIe slot, confirming that slots 4 and 6 are designated for NVMe shelf adapters, while slot 0 is for built-in Ethernet ports.