Pass the Pure Storage FAIS FlashArray-Implementation-Specialist Questions and answers with ValidTests

The FlashArray//XR2 and //XR3 architectures utilize dedicated NVRAM modules to provide the non-volatile write cache necessary for acknowledging writes safely before they are destaged to flash. These chassis are equipped with multiple NVRAM bays (labeled NVB0 through NVB3).

For standard configurations, specifically the //X10, //X20, and //X50 models, the system requires a redundant pair of NVRAM modules to function. These arealways installed in NVRAM bays 0 and 1.

Bays 0 and 1form the primary high-availability pair. If one fails, the other retains the data, and the system can continue to operate (though often in write-through mode or with alerts).

Higher-end models like the //X70 and //X90 populate all four bays (0-3) to provide the larger write buffer required for their higher throughput capabilities.

However, since the question asks which bays arealwayspopulated (i.e., the minimum requirement for the platform to function across the board), the answer is the foundational pair in slots 0 and 1. An Implementation Engineer must ensure these specific slots are populated first during any chassis maintenance or upgrade.

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To view the currently configured Network Time Protocol (NTP) servers on a FlashArray, the correct command ispurearray list --ntpserver.

Command Hierarchy:While NTP is a networking function, in the Purity CLI object model, time synchronization is considered a global array attribute rather than a specific interface setting. Therefore, it falls under the purearray command namespace.

Usage:Running purearray list --ntpserver returns a list of the IP addresses or FQDNs of the time servers the array is currently using to sync its system clock.

Invalid Options:

purenetwork list (Option B) displays IP interface configurations (IPs, subnets, gateways) but does not list service-level pointers like NTP.

puredns list (Option A) is strictly for DNS nameservers and suffix configurations.

Importance:Verifying NTP is critical for log timestamp accuracy, ActiveCluster mediation, and Kerberos authentication.

The FlashArray//E (and the //XR4/R5 family) utilizes a modern architecture that moves away from the dedicated NVRAM modules found in legacy generations (like the //XR2 and //XR3). In those older systems, NVRAM was housed in specific PCIe cards plugged into the chassis.

In the FlashArray//E architecture, the Non-Volatile RAM (write buffer) functionality isDistributeddirectly onto the storage media itself. These specialized drives are calledDFMDs(DirectFlash Modules with Distributed NVRAM).

By integrating the NVRAM into the DFMs, the array scales its write buffer cache linearly with capacity and removes the bottleneck of fixed NVRAM slots in the chassis. This allows for higher density and simplified hardware designs. During installation or inventory, engineers must distinguish between standard DFMs (which store data only) and DFMDs (which store data and act as the write cache), ensuring the correct number of DFMDs are present to form the system quorum.

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Before performing a physical card addition (I/O expansion) on a specific controller, it should be in theSecondarystate.

The procedure for adding hardware to a FlashArray is a sequential, non-disruptive process. You cannot add a card to thePrimarycontroller because it is actively handling host I/O; opening it would cause a service outage. Therefore, the Implementation Engineer must first verify the cluster health and, if necessary, perform a manual failover (pureadm make --secondary) to ensure the target controller isSecondary.

Once the controller is Secondary (passing no I/O), the engineer proceeds to stop the Purity software (pureadm stop) and/or power down the controller to safely install the PCIe card. While the physical work happens when the controller is powered off/inactive, "Secondary" is the correct operational starting state required to begin the maintenance workflow safely. "Standby" is often used to refer to a controller that is powered on but not running Purity, which is a subsequent step, not the initial prerequisite state relative to the cluster role.

While modern FlashArrays (like the XR4 and XL series) primarily use NVMe-oF/RoCE for backend connectivity, specific configurations or legacy support scenarios may still require aSAS HBA(Serial Attached SCSI Host Bus Adapter), for example, when connecting to older SAS-based expansion shelves during a migration or hybrid configuration.

ForR4B revision controllers(a specific hardware revision of the Gen 4 controller), the strict hardware addressing map requires that any SAS HBA be installed inPCIe Slot 1.

Slot 1provides the specific PCIe lane routing and BIOS interrupts required for the legacy SAS controller to be recognized and function without conflicting with the native NVMe fabric.

Installing the card in Slot 0 (typically reserved for RoCE/Ethernet backend) or Slot 4 would likely result in the card being ignored by Purity or causing boot errors due to resource conflict.

After a controller upgrade or any maintenance that involves path failovers, it is critical to verify that the host multipathing software has restored connectivity to all paths and that I/O is being distributed correctly. The specific command to validate this in Purity ispurehost monitor --balance.

purehost monitor --balance: This command provides a real-time view of I/O statistics per initiator (host path). It highlights imbalances where one path might be taking zero traffic while others are overloaded, which typically indicates a pathing configuration issue, a bad cable, or a host that has not correctly rediscovered the path after the controller reboot.

purehost list simply displays configured hosts, not live performance data.

pureport list displays the status of array ports but does not show the per-host I/O distribution required to verify "balance."

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When adding a second DirectFlash Shelf to aFlashArray//XL, the connectivity utilizesPCIe Slot 6(in conjunction with Slot 0).

FlashArray//XL Architecture:The //XL chassis distributes its backend NVMe-oF (100GbE RoCE) connectivity across two dedicated PCIe slots to ensure redundancy and maximum bandwidth. As established in hardware diagrams,Slot 0(lower riser) andSlot 6(upper riser) are the designated slots for the 2-port 100GbE backend cards.

Expansion Logic:

First Shelf:Typically connects to Port 0 of the card in Slot 0 and Port 0 of the card in Slot 6 (providing HA).

Second Shelf:Connects to the remaining ports (Port 1) on thesame cardsin Slot 0 and Slot 6.

Exam Context:In the context of "which slot must be used" for the expansion or specifically highlighting the secondary backend slot distinct from the primary host slots,Slot 6is the correct identifier for the backend expansion capability on the //XL. Options A (Slot 0) is the primary, but C (Slot 6) is often the specific answer required to demonstrate knowledge of the //XL's unique split-riser backend layout compared to legacy arrays.

Data evacuation is a background process used to move data off specific physical media (like a shelf or data pack) so it can be removed safely. Purity is designed to handle dynamic changes to evacuation requests efficiently.

If an evacuation is already running and additional hardware needs to be evacuated, the Implementation Engineer does not need to stop the current job or wait for it to finish. The correct procedure is toissue a new evacuation commandspecifying the additional packs or shelves. Purity will intelligently update the existing background job to include the new targets, queuing the data movement logic to ensure all specified hardware is cleared. This "add-to-flight" capability saves time and administrative overhead compared to cancelling and restarting the entire workflow.

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The correct procedure is tomove the 20TB chassis Data Pack (DP) to the external shelf (SH0)to free up a chassis slot for the new high-capacity pack.

Capacity Analysis:The array has ~52TB total raw capacity (20+10+22) and is 83% full (~43TB used).

Constraint:You cannot simply "evac" the chassis drives (Option A) because the remaining capacity (22TB in the shelf) is insufficient to hold the 43TB of data. Similarly, evacuating the shelf first (Option C) leaves only 30TB in the chassis, which is also insufficient.

The Solution (Option B):

Relocate:The engineer physically moves the 20TB pack from the Chassis (Slot 0) to the empty slot in Shelf 0 (SH0). This is a supported non-disruptive operation (assuming compatible shelf/pack types).

Install:This clears Chassis Slot 0, allowing the installation of the massive91TB Data Pack.

Consolidate:The system now has huge capacity (10+20+22+91). Purity can safely evacuate the old 10TB pack (Chassis) and the external shelf packs (20+22) into the new 91TB internal capacity.

Final State:The array ends up with the single 91TB pack in the chassis, meeting the "X50R2-91/0" target configuration.

Upon verifying that a hardware upgrade is successfully completed and the system is stable, the command to remove the maintenance suppression ispurealert untag --maintenance.

During upgrade activities, engineers often apply a "maintenance" tag or flag to the alert system to prevent the generation of "noise" (false positive alerts) that would otherwise be triggered by expected events like controller failovers, link downs, or path fluctuations. This suppression ensures that the customer and Pure Support are not flooded with critical tickets for planned work.

Once the work is done, it is critical to remove this suppression so the array resumes normal monitoring. The purealert command with the untag verb and the specific --maintenance flag is the correct syntax to clear this state. Options A and C use invalid syntax (--cancel or --unset) that is not recognized by the Purity CLI for this specific alert management function. Failing to run this command leaves the array in a state where genuine failures might be masked, violating the "Always-On" monitoring standard.