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

The FlashArray//XR4 introduces a new chassis layout and PCIe slot numbering scheme compared to previous generations. For expansion connectivity, specific slots are designated for the backend SAS or Ethernet/RoCE fabric cards that connect to DirectFlash Shelves.

According to the //XR4 hardware guide and expansion best practices, PCIe slot 3 is the designated location for the additional expansion interface card required when adding a second DirectFlash Shelf (or for specific shelf configurations). Slots 0 and 1 are often reserved for host I/O or other functions, and slot numbering/priority is strict to ensure the BIOS and Purity software correctly recognize the card function.

Installing the card in the wrong slot (like slot 0 or 4, if those are reserved for other uses or primary I/O) could result in the shelf not being detected, the array failing to boot, or suboptimal performance due to PCIe lane allocation. Therefore, the engineer must install the DFS expansion card into PCIe slot 3 and cable the second shelf to the ports on that specific card to ensure a supported and functional configuration.

In the architectural evolution from FlashArray//XR2 and //XR3 to the FlashArray//XR4, Pure Storage made significant changes to the controller's rear panel and I/O design to accommodate higher performance and PCIe Gen 4 capabilities. One of the most critical changes for an Implementation Engineer to plan for during a hardware Non-Disruptive Upgrade (NDU) is the removal of the onboard, default iSCSI ports that were present on previous generations. On //XR2 and //XR3 controllers, there were onboard Ethernet ports often used for iSCSI host connectivity without requiring a discrete PCIe adapter. However, the //XR4 controller design removes these dedicated onboard iSCSI ports to streamline the motherboard design and shift host I/O strictly to PCIe add-in cards. The //XR4 retains onboard ports specifically for Management (Mgmt) and Replication connectivity, ensuring that administrative access and array-to-array replication can still be maintained without additional hardware. Consequently, if a customer wasrelying solely on the onboard ports for iSCSI traffic on their legacy //XR2 or //XR3, the Bill of Materials (BOM) for the upgrade to //XR4 must include discrete Ethernet/iSCSI PCIe cards to migrate those connections. Failure to identify this architectural difference during the pre-upgrade inventory can result in a loss of host connectivity or an inability to cable the new controllers correctly, as the expected physical ports simply will not exist on the new chassis

The FlashArray//XL series (such as the XL130R5) utilizes a modern backend connectivity architecture for its expansion shelves, specifically the DirectFlash Shelf (DFS). Unlike older generations that might have used SAS (Serial Attached SCSI) forshelf connectivity, the //XL architecture relies on high-speed Ethernet with RoCE (RDMA over Converged Ethernet) to communicate with external media shelves. This ensures that the NVMe drives in the shelf perform with the same low latency as those in the head unit. To attach a DirectFlash Shelf to a FlashArray//XL130R5, the chassis must be populated with specific PCIe interface cards designated forshelf back-end connectivity. The correct part for this is the FA-XL100G Ethernet/RoCE 2-Port card. This card provides the necessary 100 Gigabit Ethernet bandwidth and RoCE protocol support required for the NVMe-oF (NVMe over Fabrics) backend fabric that Pure Storage uses. It is crucial to distinguish this from host-facing cards. While an "iSCSI/RoCE" card exists, the shelf connectivity specifically utilizes the "Ethernet/RoCE" designation in the BOM to differentiate backend fabric ports from frontend host ports. The 200G options are generally reserved for host connectivity or inter-array clustering in specific high-performance setups, but the standard validated card for connecting the DFS to the //XL130R5 is the 100G Ethernet/RoCE adapter. Verifying this line item on the BOM prevents onsite delays where the engineer might otherwise find themselves with incompatible ports for the expansion shelves. 

For a Dark Site customer (where Remote Assist and PhoneHome are disabled), the appropriate next step before performing a shelf evacuation is to use the evac_checks script.

Risk Mitigation: Evacuating a shelf is a resource-intensive operation that permanently removes physical capacity from the system. In a connected environment, Pure Support runs remote diagnostics to verify the array has enough free space and system resources to handle the evacuation safely.

Dark Site Procedure: Since Support cannot log in remotely, the Implementation Engineer must manually run the evac_checks python script (typically loaded via USB or available in the Purity toolkit). This script performs the equivalent validation: checking effectively used capacity, dedup ratios, and system load to predict if the remaining drives can absorb the data from Shelf 01 without filling the array to 100% or causing performance degradation. Relying solely on a generic percentage (Option B or C) is dangerous because it doesn't account for data reduction overhead or specific RAID overheads.

The pureadm command suite is the primary CLI tool used by Implementation Engineers and Support to manage the Purity operating environment's services and high-availability states. After a controller reboot---whether part of a hardware replacement, NDU, or fresh install---it is critical to verify that the Purity software stack has initialized correctly and that all sub-services (such as the I/O handling process, management daemon, and scut) are running.

The specific command pureadm list is the correct syntax to display a summary of the Purity services and their current status (e.g., running, stable, or stopped) on the local controller. This command provides a clean, immediate view of the service stack's health. If the output shows all expected services as 'running,' the engineer can confirm the controller has successfully rejoined the cluster and is ready to handle operations.

While pureadm alone might print help text and pureadm status is often a valid guess for other systems, the strict syntax for FlashArray implementation verification relies on pureadm list. This step is a standard part of the 'Health Check' procedures found in upgrade guides. Failing to verify service status before proceeding (e.g., failing over to the other controller) could lead to an outage if the rebooted controller hasn't actually fully started its data services. Therefore, pureadm list is the validation checkpoint before declaring the controller healthy.