Pure Storage FlashArray-Implementation-Specialist - Pure Certified FlashArray Implementation Specialist (FAIS) Exam

Understanding the physical power requirements of the Pure Storage FlashArray//XL is critical during the site planning and rack-and-stack phases of an installation. Unlike the standard 3U FlashArray//X or //C models, which operate on two power supplies (one per controller for standard 1+1 redundancy), the FlashArray//XL represents a significant leap in compute density and power consumption.

Housed in a massive 5U chassis, the //XL architecture features highly powerful multi-core Intel processors, expansive memory footprints, and a dense PCIe Gen 4 topology to support massive NVMe-oF backend scaling. To safely deliver and distribute the necessary wattage to these components while maintaining enterprise-grade high availability, the //XL chassis is equipped with four dedicated Power Supply Units (PSUs).

During physical installation, the Implementation Engineer must connect all four C20 power receptacles to the rack's Power Distribution Units (PDUs). Best practices mandate that these four connections are split across separate PDUs (e.g., PSUs 0 and 2 on PDU A, and PSUs 1 and 3 on PDU B) to ensure N+N power redundancy. Attempting to power the //XL chassis with only two connections will trigger severe hardware fault alerts within Purity and may prevent the array from drawing enough power to safely initialize both controllers and the 40 front-loading DirectFlash Module with Distributed NVRAM (DFMD) slots.

When new capacity (a data pack) is physically installed into a FlashArray, the drives are detected by the system but are not automatically added to the storage pool to prevent accidental data overwrites or configuration errors. They appear in an "unadmitted" state.

To logically add these drives to the array's capacity, the Implementation Engineer must explicitly admit them. The command to perform this action is purearray drive admit (or puredrive admit in some contexts, but purearray drive admit is the specific option provided and valid). This command triggers the Purity software to format the new drives, add them to the system's write groups, and begin rebalancing data across the expanded capacity. Without running this admission command, the drives will remain visible but unusable for storage.

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Understanding the hardware architecture of the Pure Storage FlashArray//E is crucial for proper deployment and capacity management. The FlashArray//E (and FlashBlade//E) family was specifically engineered to deliver an all-flash solution for capacity-optimized, tier-2 workloads and unstructured data repositories, aiming to replace legacy spinning disk (HDD) environments entirely.

To achieve this massive storage density at a disruptive price point, the //E series exclusively utilizes Quad-Level Cell (QLC) flash. While older arrays (like the //X50) use strictly dedicated NVRAM modules centrally located in the chassis, and higher-end TLC arrays (like the //XL) use DirectFlash Modules with Distributed NVRAM (DFMDs), the FlashArray//E utilizes a highly specialized drive.

On the FlashArray//E, the non-volatile write cache is distributed across DFMes . "DFMe" is the specific Pure Storage hardware nomenclature for a QLC-based DirectFlash Module that includes integrated, distributed NVRAM. By moving the NVRAM directly onto the QLC capacity modules, the //E architecture eliminates the need for dedicated NVRAM bays, streamlines the write path, and allows the write cache bandwidth to scale linearly as the customer adds more capacity to the system.

In a Non-Disruptive Upgrade (NDU), ensuring that the host is correctly multipathed and balancing I/O across all paths is critical before taking a controller down. If a host is only using paths to the controller about to be rebooted (CT0, for example), taking that controller offline would cause an outage.

The command iobalance --sampletime 30 (or its wrapper purehost monitor --balance) is the standard tool used during the upgrade procedure to validate this state.

iobalance : This script samples the I/O throughput on all ports for a specified duration (e.g., 30 seconds).

It analyzes the distribution of I/O. If it detects that I/O is heavily skewed or missing entirely on the "secondary" paths (the ones that will survive the reboot), it flags a warning.

This allows the Implementation Engineer to pause and remediate the host multipathing configuration (e.g., fixing a bad cable or zoning issue) before proceeding with the controller removal, ensuring the NDU remains truly non-disruptive.

To ensure that all volumes connected to a specific host are automatically protected, the Implementation Engineer should add the Host object as a member of the Protection Group (PGroup) .

Purity's protection policy logic allows for membership at different granularities:

Volume Membership: You can add individual volumes to a PGroup. However, if a new volume is provisioned and attached to the host later, it will not be protected until an admin manually adds it to the PGroup (making Option A and B manual, error-prone processes).

Host/Host Group Membership: By adding the Host entity to the Protection Group, Purity applies a policy inheritance rule. Any volume currently connected to that host—and crucially, any volume attached in the future —automatically inherits the protection policy (snapshot schedule, replication target) of that group. This "set and forget" configuration is the best practice for ensuring compliance and data safety without requiring manual intervention for every provisioning task.

On a new FlashArray//XR4 installation, the Implementation Engineer must run the cobalt_check.py script 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.

To reduce SafeMode protections (such as shortening the retention period or disabling the eradication timer), two authorized SafeMode approvers must authenticate and approve the request via Pure1 step-up authentication .

SafeMode is a ransomware protection feature designed to prevent the accidental or malicious deletion of snapshots. Because reducing these protections weakens the array's security posture, Pure Storage enforces a strict "Ratchet" authorization process.

The Process: Unlike standard support requests, a single admin or local user cannot authorize this change (making Option C incorrect). The customer must have previously designated specific individuals as "SafeMode Approvers" in their Pure1 portal.

Authorization: When a request to weaken the policy is made, Pure Support triggers a verification workflow. Two of these designated approvers must log into Pure1 and perform a secondary authentication (often involving a PIN or TOTP) to explicitly "sign off" on the reduction. This "two-person rule" ensures that a compromised credential or a rogue insider cannot unilaterally expose the organization's backup data to destruction.

The FlashArray//E connects to its DirectFlash Shelves (DFS) using 25Gb Ethernet (RoCE) .

The FlashArray//E is the "Capacity Optimized" member of the FlashArray family, designed to replace spinning disk repositories with all-flash efficiency. While the high-performance FlashArray//XL utilizes 100GbE for its backend NVMe-oF connectivity to maximize throughput for mission-critical databases, the //E prioritizes cost-efficiency, density, and power consumption.

Architecture: To maintain this efficiency balance, the backend connectivity for expansion shelves on the //E platform is standardized on 25GbE . This provides ample bandwidth for the QLC-based workloads (typically unstructured data, repository, or Tier 2 block) without the higher cost and power draw of 100GbE optics and controllers.

Comparison: Option A (40G) is a legacy QSFP standard not used in modern Pure backend designs. Option C (100G) is reserved for the performance-tier //XL and high-end //X models.

During a Pure Storage FlashArray Hardware Non-Disruptive Upgrade (HWNDU), controllers must be seamlessly transitioned to ensure continuous host I/O. The correct procedure to execute a planned controller failover on an array running Purity 6.9.2+ involves using the purewes command suite. "WES" (Wessex) represents the internal architecture and toolset utilized by Pure Storage engineering and support to manipulate high-availability states and controller roles directly.

While standard array management utilizes purecli, HWNDUs require specific, low-level overrides to safely manipulate primary and secondary designations without disrupting active multipathing. To transition the current primary controller (e.g., CT0) to a secondary role, the Implementation Engineer must execute purewes controller setattr --verify-array < host-name > ct0 --mode secondary.

This command initiates a graceful giveback of all backend drive resources and frontend host I/O responsibilities to the partner controller (CT1). Once CT1 fully assumes the primary role, CT0 enters a ready secondary state, making it safe to power down, un-cable, and physically replace. The --verify-array flag ensures that the engineer is targeting the correct array by explicitly requiring the hostname, acting as a critical safeguard against accidental failovers on the wrong system during multi-array engagements. Options B, C, and D introduce fictitious command variations that do not exist within the Purity CLI framework for this specific hardware replacement step.

When executing a Hardware Non-Disruptive Upgrade (HWNDU) to a new chassis generation, such as moving to a FlashArray//XR5, the new controllers must be properly prepped to join the existing, older-generation cluster. The correct sequence of operations is critical to prevent the cluster from rejecting the mismatched hardware.

Once the new //XR5 controller is physically inserted into the slot of the removed older controller, the Implementation Engineer must first install the correct target version of the Purity//FA operating system locally using the pureinstall command via the KVM console. After Purity is successfully installed, but strictly before the controller is logically initialized to join the cluster (via the puresetup secondary command), the engineer must execute the start_ndu controller-ndu script.

This script applies specific internal HWNDU tunables—such as relaxing hardware mismatch checks, bypassing specific alert monitors, and adjusting heartbeat timeouts. Setting these tunables ensures that when the controller is finally initialized, the surviving primary controller safely accepts it as a valid secondary partner without triggering a system fault, hardware rejection, or disrupting active host I/O.