EMC D-PWF-DS-23 - Dell PowerFlex Design 2023 Exam

The default value of paths per volume when adding an NVMe host to a PowerFlex system is 8. This setting is relevant for the configuration of multipathing, which is a method used to provide redundancy and increase availability for storage environments. When you add an NVMe host, the system allows up to 8 paths per volume to be configured by default. This is particularly important in VMware ESXi environments, where multipathing can be configured to handle failover and load balancing of storage traffic.

The reference for this information is found in the Dell PowerFlex specification sheet, which outlines the maximum paths in the multipathing driver per volume as 8 for ESXi 7.0u31. This document provides detailed specifications and configurations for the PowerFlex system, ensuring that the information is aligned with Dell’s official documentation and design guidelines for PowerFlex systems.

In a PowerFlex appliance environment, Fault Sets are used to group Storage Data Servers (SDSs) that are managed together as a single fault unit. When Fault Sets are employed, the distributed mesh-mirror copies of data are never placed within the same fault set1. This means that each Fault Set must have enough SDSs to ensure that data can be mirrored across different Fault Sets for redundancy.

Given that there are only five Storage Only nodes available in the described environment, and considering that each node runs an SDS, it may not be possible to create Fault Sets using all available servers if the number of Fault Sets or the distribution of SDSs across those Fault Sets does not allow for proper mirroring of data. The architecture requires a certain number of SDSs to be available to form a Fault Set that can be used for data mirroring and redundancy1.

The other options, such as requiring more than one Management node (Option A) or not having enough Compute Only nodes (Option C), are not directly related to the creation of Fault Sets. The Management node’s primary role is to manage the cluster, not to participate in Fault Sets, and Compute Only nodes do not contribute storage resources to Fault Sets.

Therefore, the correct answer is B. There are not enough Storage Only nodes, as this would prevent the architect from creating Fault Sets that meet the redundancy requirements of the PowerFlex appliance environment.