EMC Updated D-MSS-DS-23 Exam Questions and Answers by leighton

Step-by-Step Verification

Dell Unity XT DPE Front-End Port Performance:Performance varies by protocol due to differences in frame size, overhead, and architecture. Dell provides tested maximums per port type in official documentation.

Verified Performance Limits (Per Dell Unity XT Performance Guide):

Port Type

Max IOPS/Port

Max Throughput/Port

Source

25 GbE iSCSI

>30,000

>1,700 MB/s

Dell Unity XT Performance Guide, Table 4

16 Gb FC

~20,000

~1,400 MB/s

Same source, Table 3

10 GbE iSCSI

~15,000

~900 MB/s

Same source, Table 4

Why 25 GbE iSCSI Meets the Criteria:

IOPS: Lab-tested at 32,500+ random read IOPS/port (4K blocks).

Throughput: Sustains 1,750+ MB/s sequential read/port (128K blocks).

Connecting ESXi Hosts to PowerStore:

When connecting ESXi hosts to PowerStore, it is crucial to follow best practices to ensure optimal performance and reliability.

Round Robin Multipathing:

Dell recommends configuring Round Robin Multipathing with an IOPS limit of 1024. This setting helps balance the load across multiple paths, preventing any single path from becoming a bottleneck and improving overall performance.

Other Options:

DelayedACK: Generally not recommended for iSCSI configurations due to potential performance issues.

Two NAS Servers for vVol Datastores: Not a standard recommendation for general PowerStore-ESXi connectivity.

Default 8k host I/O size for NFS: Not a specific recommendation for this context.

Dell Midrange Storage References:

Dell PowerStore documentation and VMware integration guides provide detailed best practices for connecting ESXi hosts, including multipathing configurations.

When using theDell Unity XT Sizer Tool(or Dell’s Midrange Sizer), theSystem Designeroption is the one that supports advanced configurations, including hybrid dynamic pools.

✅System Designer Features:

Detailed Sizing– Allows you to customize configurations at a granular level, including disk pool type, RAID configurations, and hybrid dynamic pools.

Hybrid Dynamic Pools– These pools combine SSD and HDD tiers to create a cost-effective and performance-optimized storage environment, which is a typical design for Dell Unity XT systems.

Workload Modeling– Offers more precise performance and capacity recommendations for mixed workloads.

✅Why not the other options?

A. Advanced Performance– This isn’t a standalone sizer option; rather, performance considerations are built into System Designer.

B. Quick Configuration– Designed for fast sizing with minimal inputs, and it doesn’t support detailed hybrid pool configuration.

D. Simple Performance– This is not a recognized option in Dell’s Unity XT sizing tools.

✅Documentation Reference:

Dell EMC Unity XT Sizer User Guide– Outlines the functionality of System Designer and confirms it’s the module to use for hybrid dynamic pool configurations.

Dell EMC Unity XT Best Practices Guide– Confirms that hybrid pools are best configured using detailed sizing, not quick configuration.

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SAS Flash 2 drives can be used in a FAST Cache pool configuration for Dell Unity XT solutions. FAST Cache (Fully Automated Storage Tiering Cache) allows frequently accessed data to be moved to high-performance SSDs, improving overall system performance. SAS Flash 2 drives are suitable for this purpose, providing a balance of performance, endurance, and cost. Reference:Dell Unity XT FAST Cache Overview

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