Free Pure Storage FlashArray-Implementation-Specialist Practice Exam with Questions & Answers | Set: 3

The FlashArray//XR4 utilizes onboard 100GbE RoCE (RDMA over Converged Ethernet) ports for connecting to the first loop of DirectFlash Shelves, removing the need for dedicated PCIe add-in cards for the base configuration. The port mapping for these onboard backend ports differs from previous generations.

On the //XR4 controller chassis, the specific Ethernet interfaces designated for thefirst DirectFlash Shelf loopare typically the high-numbered onboard ports. In this specific exam context and hardware revision,ETH 18 and ETH 19are identified as the correct primary backend connectivity ports .

Implementation Engineers must connect the QSFP28 cables from the "uplink" ports on the first shelf (IOM0 and IOM1) toETH18 and ETH19on the controllers (CT0 and CT1) respectively. Using incorrect ports (like ETH0/1, which are management) would result in the shelf not being detected by the storage fabric.

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The FlashArray//XL chassis is designed with specific PCIe lane allocations to support high-performance host I/O and backend connectivity. The 4-Port Fibre Channel (FC) cards are high-bandwidth devices that require x16 PCIe lanes to function at full line rate without oversubscription.

In the FlashArray//XL architecture,PCIe slots 3 and 8are designated x16 slots capable of supporting these dense 4-port host interface cards. Other slots, such as slot 5 or slot 2, may be x8 slots or reserved for other functions (like the backend SAS/Ethernet fabric or offload engines like the DCA), and thus may not physically accept or electrically support the 4-port card variant.

Implementation Engineers must adhere strictly to the slot map provided in the hardware guide. Installing a 4-port card into an unsupported slot (like an x8 slot) could lead to the card not training, the array failing to boot, or the card operating at reduced bandwidth, severely impacting host performance. Verifying the BOM and slot map forSlots 3 and 8ensures the correct electrical and thermal environment for these critical host-facing components.

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On standard 3-Rack Unit (3RU) FlashArray models (such as the FlashArray//X50, //X70, and //X90 series), the rear of the controller chassis features onboard 10GbE or 25GbE Ethernet ports. Pure Storage adheres to a strict convention for the default assignment of these ports to simplify deployment and troubleshooting.

ETH0 and ETH1are invariably reserved and configured forManagementtraffic. These are used to access the GUI, CLI, and for the array to communicate with Pure1.

ETH2 and ETH3are the designated default ports forReplicationtraffic. When an Implementation Engineer configures async or sync replication, Purity will default to looking for connectivity on these interfaces unless explicitly reconfigured. This separation ensures that heavy data replication traffic does not contend with management traffic, maintaining administrative access even during periods of high bandwidth utilization for replication. Implementation Engineers must ensure these specific physical ports are cabled to the replication network switches during installation.

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After a complex operation like a Hardware Non-Disruptive Upgrade (HWNDU), the Purity health services may occasionally stall or report generic errors like "health not responding." Standard alert commands (purealert list) might be empty or show generic "service unavailable" messages because the alerting service itself depends on the health system.

To troubleshoot this, the Implementation Engineer should dig deeper into the system's internal message log usingpuremessage list --open --hidden.

puremessageaccesses the raw message bus of the array, which captures lower-level events than standard alerts.

--hiddenis the critical flag here; it reveals internal system messages that are typically suppressed from the standard user view to avoid noise.

These hidden messages often contain the specific error codes or service failure reasons (e.g., "timeout waiting for daemon X") that explainwhythe health status is hanging. Providing this output to Pure Support significantly accelerates the root cause analysis. purearray diagnose is not a standard command for this purpose, and purealert watcher is for configuring notification recipients, not viewing log contents.

The FlashArray//XL series (specifically the //XLR5 in this context) utilizes a 100 Gigabit Ethernet-based back-end fabric to communicate with DirectFlash Shelves (DFS). This connection relies on the RoCE (RDMA over Converged Ethernet) protocol to ensure low-latency access to the external NVMe modules.

The specific PCIe interface card validated for this connectivity is often labeled in the Bill of Materials (BOM) or configuration guides as the2-Port 100GbE iSCSI/RoCEcard (or simply the 100GbE Ethernet/RoCE card depending on the specific firmware/labeling revision). Crucially, it must be a100GbEcapability card.

The //XL platform standardized on 100GbE for its shelf interconnects, moving away from the 50GbE used in some previous generations of the //X series. The 200GbE cards are typically reserved for high-speed host connectivity or clustering, not the standard shelf loop. Therefore, ensuring the BOM includes the correct 100GbE RoCE-capable cards is essential for successful shelf detection and operation during installation.

On a newFlashArray//XR4installation, the Implementation Engineer must run thecobalt_check.pyscript before executing puresetup newarray.

The FlashArray//XR4 represents a significant hardware architectural shift (internally codenamed or associated with the "Cobalt" platform generation). This platform introduces new PCIe layouts, NVMe backplanes, and controller components that require specific validation beyond the standard legacy checks. The cobalt_check.py script is a specialized hardware diagnostic tool pre-loaded on the manufacturing image of //XR4 controllers.

Its purpose is to verify that the specific hardware components of the R4 platform—such as the status of the internal NVMe interconnects, the correct population of the chassis, and the health of the new controller mainboard—are functioning within strict tolerances. Running this check ensures that the physical layer is 100% healthy before the Purity operating system attempts to initialize the database and claim the storage media. Option A (pureboot list) checks boot versions but not hardware health, and Option C (purehw list) is a general command that might not catch the specific low-level architectural issues the cobalt_check.py script is designed to identify on this specific generation.

Upgrading from a FlashArray//X to a FlashArray//XL involves a significant architectural change, often requiring a data migration or a specific "chassis replacement" workflow known as a Data-in-Place upgrade where the new chassis temporarily acts as an expansion shelf. In this specific procedure, the new FlashArray//XL chassis is not immediately populated with its final drives (DFMDs) before power-on because it first needs to be configured to accept data or join the cluster in a controlled state.

The procedure requires the Implementation Engineer to boot the FlashArray//XL chassis first and configure it intoShelf Mode (SPM). Onlyafterthe chassis is successfully running in this mode—effectively acting as a passive SAS/Ethernet attached shelf to the existing controllers—are the DirectFlash Modules (DFMd) inserted.

Inserting them earlier could cause the array to attempt a full boot sequence or initialize a new array instance, complicating the upgrade logic. By waiting until Shelf Mode is confirmed, the engineer ensures that the modules are recognized correctly as part of the migration target resources, allowing Purity to manage the layout and data redistribution correctly from the source array.

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Calculating rack space requirements is a fundamental pre-installation task. The FlashArray//XL series features a larger chassis than the //X series to accommodate its increased power, cooling, and DirectFlash capabilities.

TheFlashArray//XL Chassisitself occupies5 Rack Units (5U).

A standardDirectFlash Shelf (DFS)occupies2 Rack Units (2U).

In this scenario, the customer is installing one //XL chassis and two DFS shelves.

Calculation:

1 x //XL Chassis (5U) = 5U

2 x DirectFlash Shelves (2U each) = 4U

Total = 9U.

Therefore, the Implementation Engineer must verify that there are at least 9 contiguous Rack Units available in the cabinet. Standard best practice also suggests placing the shelves immediately above or below the controller chassis to accommodate the 3-meter maximum cable length for the backend fabric, so these 9U should ideally be in a single block.

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Service clearance is a critical physical installation requirement to ensure that components (like controllers, fans, and drives) can be safely removed and replaced without obstruction.

For theFlashArray//XR4, the specific service depth requirements are:

Front Panel:216 mm (8.5 in.). This allows sufficient room to open the bezel, unlatch drives, and pull them out of the chassis.

Rear Panel:530 mm (20.9 in.). This larger clearance is necessary because the controllers themselves (which are long, heavy components) slide out from the rear of the chassis. The engineer needs enough space to fully extract the controller without hitting a wall or another rack door.

Adhering to these clearances prevents situations where a failed controller cannot be replaced because the rack is too close to a wall.

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If physical drives need to be relocated within the array (e.g., rebalancing shelves or moving packs to specific slots to match the target configuration) as part of anXFORM (Data-in-Place) upgrade, this task should be completedafter the upgrade is completed.

Risk Management:The primary objective during the upgrade window is to successfully transition the controllers and software to the new generation (e.g., SAS to NVMe, or //M to //X) while maintaining data availability. Introducing unnecessary physical changes—like moving drives between slots—during the active controller swap adds variables and risk to the critical path.

Procedure:The standard workflow involves:

Perform the Controller Upgrade (XFORM).

Verify the new system is stable, healthy, and handling I/O correctly.

Post-Upgrade:Once the system is stable, the Implementation Engineer performs the physical drive relocation (if required) to optimize the layout or consolidate shelves. This ensures that if any issues arise from the drive movement, they are isolated from the controller upgrade process, making troubleshooting significantly easier and safer.