D-MSS-DS-23 Dell Midrange Storage Solutions Design Practice Questions
Prepare for D-MSS-DS-23 with more than an answer.
- Exam fee
- $230 USD
- Level
- Specialist
- Valid for
- Ongoing (does not expire)
Domains covered on the exam 3
- Midrange Storage Solutions Best Practices36%
- Dell Midrange Storage Solutions Planning, Sizing and Design40%
- Dell Midrange Sizing Solutions24%
- 1
A solutions architect needs to design a Dell PowerStore solution that will host a new, mission-critical containerized application managed by Kubernetes. The application requires persistent storage that can be dynamically provisioned and managed through standard Kubernetes APIs (e.g., PersistentVolumeClaims). Which PowerStore feature is essential for this design? (Select TWO)
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Correct answer: A, D
- 2
When using the PowerSizer tool to design a PowerStore X solution, what key consideration must be accounted for that is not present when sizing a PowerStore T model?
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Correct answer: C
The key differentiator of the PowerStore X model is the AppsON feature, which runs a built-in VMware ESXi hypervisor on the storage controllers. When sizing a PowerStore X, the designer must explicitly allocate a portion of the controller's CPU and memory resources to be used by the virtual machines running in AppsON. This reservation reduces the resources available for storage services, and it is a critical input in the PowerSizer tool that does not apply to PowerStore T models.
- 3
A system administrator is reviewing the backend SAS cabling for a newly installed Dell Unity XT array with one DAE. The goal is to ensure maximum redundancy. How should the SAS ports on the Storage Processors (SPs) be cabled to the DAE?
sequenceDiagram participant SPA participant SPB participant DAE SPA->>DAE: SAS Port 0 to LCC A Port 0 SPA->>DAE: SAS Port 1 to LCC B Port 0 SPB->>DAE: SAS Port 0 to LCC B Port 1 SPB->>DAE: SAS Port 1 to LCC A Port 1Show answer details
Correct answer: B
To achieve full redundancy, the backend SAS cabling must provide a path to all drives in the event of an SP failure, an LCC failure, or a cable failure. The correct method is to cross-cable the connections. For example, SPA's Port 0 connects to LCC A, while SPA's Port 1 connects to LCC B. Similarly, SPB's Port 0 connects to LCC B, and its Port 1 connects to LCC A. This ensures that each SP has a path to each LCC, providing tolerance for multiple component failures.
- 4
During the workload characterization phase for a new storage design, a consultant uses an analysis tool and records the following metrics for the primary application: average IOPS of 15,000, a read/write ratio of 3:1, and an average I/O size of 32 KB. What is the approximate throughput requirement for this workload in MB/s?
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Correct answer: C
Throughput can be calculated by multiplying the total IOPS by the average I/O size. The read/write ratio is important for cache analysis but not for this specific calculation.
Calculation: 15,000 IOPS * 32 KB/IO = 480,000 KB/s.
To convert KB/s to MB/s, divide by 1024: 480,000 KB/s / 1024 KB/MB ≈ 468.75 MB/s. - 5
A customer is implementing a Dell PowerStore array and wants to ensure that if a single drive fails, the system can rebuild the data from that drive without impacting the overall RAID protection level of the storage pool during the rebuild process. Which feature of PowerStore's dynamic resiliency enables this?
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Correct answer: C
PowerStore does not use traditional dedicated hot spares. Instead, it employs dynamic resiliency with distributed sparing. Spare space equivalent to one drive's capacity is distributed across all drives in the appliance. When a drive fails, the data is rebuilt into this distributed spare space across the remaining healthy drives. This approach provides faster rebuild times and maintains the original level of RAID protection (e.g., dual parity) even while the rebuild is in progress.
- 6
When designing a Dell Unity XT storage pool for a general-purpose virtualized environment, which RAID level typically offers the best balance of performance, capacity utilization, and protection for all-flash configurations?
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Correct answer: B
For all-flash dynamic pools in a general-purpose environment, RAID 5 is often the recommended starting point. It provides a good balance of performance (especially with SSDs where the write penalty is less severe), excellent capacity efficiency (only one drive's worth of capacity used for parity per RAID extent), and single-drive failure protection. While RAID 6 offers more protection and RAID 10 offers better write performance, RAID 5 is the most balanced choice for cost-conscious, general-purpose workloads on reliable flash media.
- 7
Case Study:
A university is planning to deploy a new Dell PowerStore 3000X to support a research project that requires running data analytics applications directly on the storage array to minimize data movement. The research team will use a mix of containerized applications and traditional virtual machines. They have projected a need for 10 vCPUs and 64 GB of RAM for their applications running within AppsON.
The solutions architect is using the PowerSizer tool to validate the configuration. The tool indicates that a standard PowerStore 3000X appliance has a total of 32 vCPUs and 384 GB of RAM available per appliance (both nodes combined). The workload is expected to generate significant storage I/O.
What is the most important design consideration for the architect when finalizing the PowerStore 3000X configuration to ensure both the research applications and the storage services perform adequately?
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Correct answer: B
When designing a PowerStore X solution with AppsON, the critical task is to balance the resources between the user applications (VMs/containers) and the PowerStoreOS storage services. The architect must reserve the required compute resources (10 vCPUs, 64 GB RAM) for AppsON. The PowerSizer tool will then calculate if the remaining resources (22 vCPUs, 320 GB RAM) are sufficient to handle the projected storage I/O. Failing to perform this balancing act can lead to resource contention, where either the applications or the storage services are starved of CPU/memory, resulting in poor performance for both.
- 8
A solutions architect is designing a PowerStore T solution for a VDI environment with 2,000 persistent desktops. The primary design goal is to minimize storage latency while ensuring predictable performance during boot storms. The architect is using the PowerSizer tool for the design. Which drive configuration should be prioritized in the design to meet these requirements?
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Correct answer: C
For latency-sensitive workloads like VDI, especially during boot storms, an all-NVMe SSD configuration in the base enclosure provides the lowest latency and highest IOPS. NVMe drives communicate directly over the PCIe bus, bypassing the traditional SAS controller and protocol overhead, which is ideal for handling the highly random I/O patterns of a boot storm. While SCM offers even lower latency, a full enclosure of NVMe SSDs is the most direct and effective solution presented for this specific requirement. SAS SSDs would introduce higher latency compared to NVMe.
- 9
During a site evaluation for a new Dell Unity XT 880F array, a consultant notes that the customer's datacenter has limited rack space and only provides 208V single-phase power. The proposed solution includes the 2U base array and three 2U 25-drive DAEs. What is the most critical environmental remediation step the customer must perform before installation?
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Correct answer: C
The proposed configuration consists of one 2U base array and three 2U DAEs, totaling 8U of rack space. The most critical first step is to ensure there are 8U of contiguous space available in a single rack to accommodate the entire system, as splitting the base array and its DAEs across racks is not a standard or recommended practice. Power and weight are important, but confirming the physical space is the primary constraint mentioned and the first one to validate.
- 10
A storage administrator is configuring asynchronous replication for a critical file system between two Dell Unity XT arrays. The primary business requirement is to minimize the potential for data loss in a disaster, which translates to the lowest possible Recovery Point Objective (RPO). Which setting should be configured for the replication session to meet this requirement?
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Correct answer: B
For asynchronous replication, the RPO defines the maximum amount of data, measured in time, that may be lost. To minimize data loss, the administrator must configure the lowest possible RPO supported by the system and the network link. Dell Unity XT supports an RPO as low as 5 minutes for asynchronous replication. This ensures that the data on the destination is at most 5 minutes behind the source, providing the best protection against data loss in this scenario.
