Pure Storage FlashArray-Storage-Professional Exam Questions

Replication Fundamentals: On a Pure Storage FlashArray, replication is a snapshot-based process. To replicate a Protection Group (pgroup) to a target array, the system must first create a point-in-time snapshot of the volumes within that group on the source array.

The 'Immutable' Rule: Even if the Local Snapshot Schedule is disabled, the act of replicating requires the existence of a local snapshot to serve as the 'base' or 'source' for the data transfer. Purity does not stream data directly from the active volume to the wire; it creates a snapshot and then replicates the unique blocks contained in that snapshot.

Accounting for Local Copies: When a Protection Group is configured for replication, every snapshot generated by the Replication Schedule is stored locally on the source array. These snapshots will remain on the source array until they are aged out according to the Local Retention policy (even if the local schedule itself is off, the retention policy still applies to those replicated snapshots).

Visibility: If you navigate to the Protection Group in the Purity GUI, you will see these snapshots listed under the 'Snapshots' tab. They are functionally identical to local snapshots, meaning they can be used for local clones or restores without needing to pull data back from the target array.

Why Option A and C are incorrect: * Option A: If 0 snapshots were stored, there would be nothing to replicate.

Option C: While Purity uses the most recent snapshot as a reference for delta-tracking, it keeps the entire history of snapshots defined by your retention policy, not just a single one.

The ActiveCluster Mediator (whether it is the Pure1 Cloud Mediator or the On-Premises VM) is a lightweight tie-breaker that communicates continuously with the management interfaces of both FlashArrays. If it was previously online and suddenly reports as 'unreachable' from both arrays simultaneously, the issue is almost always caused by a network interruption or firewall rule change blocking the required communication ports between the arrays' management IP addresses and the Mediator VM.

If a network firewall is suddenly configured to drop or deny outbound TCP traffic (such as port 80/443 depending on the specific HTTP/HTTPS discovery and heartbeat configuration) from the FlashArrays to the ESXi-hosted Mediator, the arrays will fail to send their heartbeats, causing the mediator status to drop to 'unreachable.'

Here is why the other options are incorrect:

Fibre Channel (FC) zoning or network access has not been created properly for the host (A): The Mediator is completely independent of the front-end host storage fabric (Fibre Channel or iSCSI). Host zoning issues would prevent the ESXi server from seeing its volumes, but it would not cause the FlashArrays to lose management network connectivity to the Mediator.

The mediator does not reside within a Pure datastore (B): This is actually a strict best practice and requirement. Pure Storage explicitly states that the On-Premises Mediator VM must be deployed in a separate (third) failure domain. It should not reside on the ActiveCluster mirrored datastore, because a site-wide SAN failure would take the mediator offline exactly when it is needed most. Therefore, not residing on a Pure datastore is the correct setup, not a cause for an outage.

VMFS UUID Conflict: When you create a volume from a snapshot on a FlashArray, the data is a block-for-block copy of the original. This includes the VMFS metadata and the unique identifier (UUID) of the datastore.

ESXi Protection Mechanism: When an ESXi host sees a volume that contains a VMFS signature identical to one already mounted (or one it has seen before but on a different device ID), it flags the volume as a 'snapshot.' To prevent data corruption or VM identity conflicts, VMware will not automatically mount this 'duplicate' volume.

The Resignaturing Process: By choosing to Resignature the volume (via the 'Mount Datastore' wizard in vCenter or the ESXi CLI), VMware assigns a new, unique UUID to the VMFS volume. This allows the host to treat it as a distinct, independent datastore.

Why Option B is incorrect: Reformatting the volume would indeed allow it to be mounted, but it would destroy all the data you just copied from the snapshot, defeating the purpose of the operation.

Why Option C is incorrect: While there are advanced settings in VMware (like LVM.enableResignature), they don't solve the issue of the operation 'failing' during a standard mount attempt; they simply change how the host behaves. Resignaturing is the standard, safe, and recommended workflow for mounting snapshot copies in a VMware environment.

When configuring NVMe/TCP (or iSCSI) for optimal performance on a Pure Storage FlashArray, configuring Jumbo Frames (an MTU of 9000) end-to-end is a standard best practice.

The command ping -M do -s 8972 <ip_addr> is specifically used to verify Jumbo Frame configuration across the network.

The -M do flag sets the 'Do Not Fragment' (DF) bit, meaning the network is not allowed to break the packet into smaller pieces.

The -s 8972 flag sets the ICMP data payload to 8972 bytes. When you add the standard 8-byte ICMP header and the 20-byte IP header, the total packet size equals exactly 9000 bytes.

If this ping command fails, it indicates that somewhere along the network path between the host (initiator) and the FlashArray (target), a switch port, router, or network interface is not configured to support an MTU of 9000. The packet is being dropped because it is too large and cannot be fragmented. The administrator must verify the MTU settings on every network hop (switches, routers, and host NICs) to resolve the issue.

Here is why the other options are incorrect:

Engage support to enable NVME/ TCP services (A): The failure of a Jumbo Frame ping test is a Layer 2/Layer 3 network configuration issue, not an indicator that the NVMe/TCP storage protocol service is disabled on the array.

Run the command from the target (C): While pinging from the FlashArray back to the host is a valid secondary troubleshooting step, it will likely also fail if the network path doesn't support Jumbo Frames. The actual resolution is to fix the MTU on the network hops.

According to the official Pure Storage FlashArray Asynchronous Replication Configuration and Best Practices Guide, the proper and immediate method to halt an active, in-progress asynchronous replication transfer is by disallowing the protection group at the target.

When you navigate to the target FlashArray and disallow the specific Protection Group, Purity immediately breaks the replication authorization for that group. If there is an in-progress snapshot transfer occurring at that exact moment, the transfer is immediately stopped, and the partially transferred snapshot data is discarded on the target side.

Here is why the other options are incorrect:

Disabling the replication schedule (B): Toggling the replication schedule to 'Disabled' only prevents future scheduled snapshots from being created and sent. It does not kill or interrupt a replication transfer that is already currently in progress.

Removing the volume member from a protection group (A): Modifying the members of a protection group updates the configuration for the next snapshot cycle. It does not actively abort the transmission of the current point-in-time snapshot that the array is already busy sending over the WAN.