D-UN-DY-23 Practice Questions

Dell EMC Unity's Fully Automated Storage Tiering for Virtual Pools (FAST VP) allows administrators to control the data relocation process. The relocation rate can be set to Low, Medium, or High, which adjusts the system resource impact of the tiering activity. This setting provides flexibility to balance performance optimization with the overhead of data movement, allowing administrators to prioritize I/O for production workloads during business hours by selecting a lower rate.

A. FAST VP data relocation runs on a scheduled basis, typically outside of peak hours, not continuously at all times.

B. FAST VP on Unity systems uses a data slice (or chunk) size of 256 MB for data movement, not 1 GB.

D. FAST VP is a feature enabled and configured at the storage pool level, not on individual LUNs.

1. Dell EMC Unity: FAST Technology A Detailed Review. (April 2017). Page 11

"Relocation Rate".

2. Dell EMC Unity Family Unisphere Online Help. (Accessed for Unity OE version 5.x). Section: "Pool Properties > Tiers tab"

Description of "Data Relocation Rate".

The Dell EMC Unity 380 and 380F models support a specific range of I/O modules for connectivity. According to the official hardware specifications, these models can be configured with a 4-port 12 Gb/s SAS I/O module for backend expansion and a 4-port 10 GbE Base-T I/O module for host connectivity. Higher-speed options like 32 Gb/s Fibre Channel and 100 GbE are reserved for the higher-end Unity XT models (e.g., 880/880F).

A. The 2-Port 100 GbE I/O module is not supported on the Unity 380/380F platform; it is available on higher-end models.

B. The 32 Gb/s Fibre Channel I/O module is not supported on the Unity 380/380F; this model supports up to 16 Gb/s FC.

D. This option combines two unsupported high-speed modules (32 Gb/s FC and 100 GbE) for the Unity 380/380F model.

1. Dell EMC Unity XT 380/380F Specification Sheet. (August 2022). Page 2

"I/O Modules Supported per Storage Processor".

2. Dell EMC Unity Family Hardware Information Guide. (Version for Unity OE 5.x). Section: "I/O Modules > I/O Module Specifications"

Table for Unity 380/380F supported modules.

When configuring an NFS share on a Dell Unity XT system, administrators must define which hosts are allowed to access the share. This is managed through the "Host Access" settings, where specific hosts, subnets, or netgroups can be granted read-only, read/write, or root-level permissions. This is a fundamental and required step for controlling access to NFS exports, ensuring that only authorized clients can mount and interact with the file system.

A. Access-Based Enumeration (ABE) is a feature for SMB/CIFS shares that filters directory visibility based on user permissions; it is not a native feature of NFS share configuration on Unity.

B. Protocol Encryption for NFS on Unity is typically handled through Kerberos configuration (krb5p), not as a simple, direct share-level setting like it is for SMB 3.0.

D. Distributed File System (DFS) is a Microsoft technology used to create a logical namespace for SMB/CIFS shares across multiple servers and is not applicable to NFS.

1. Dell Unity XT Series Unisphere Online Help (Version 5.3). Section: "Create an NFS share". This section details the "Host Access" tab where permissions are configured for specific hosts.

2. Dell White Paper: "Dell Unity: File Systems" (H15268.5). Page 15

Section "NFS Share Creation". The document describes the process of creating an NFS share

which includes configuring default access and adding host-specific access rules.

The total cache in a Dell Unity XT system is the sum of its System Cache (DRAM) and its FAST Cache (Flash drives). In this scenario, the System Cache is 192 GB and the FAST Cache is 1.2 TB. The total cache capacity is calculated as 1.2 TB + 192 GB. Converting 192 GB to TB (192 / 1024 ≈ 0.1875 TB) and adding it to the FAST Cache gives a total of approximately 1.39 TB. Note that FAST Cache is not used for all-flash pools; however, the question asks for the total available cache in the system.

A. 6.0 TB is an arbitrary value with no basis in the provided system specifications.

C. 3.58 TB is an arbitrary value with no basis in the provided system specifications.

D. 3.2 TB is an arbitrary value with no basis in the provided system specifications.

- Dell EMC Unity: FAST Technology Overview

White Paper (April 2020)

Page 5

"System Cache": "System cache is the DRAM in the storage processors." Page 6

"FAST Cache": "FAST Cache is a feature that uses Flash drives to extend the capacity of the system cache."

- Dell Unity XT 480/F Specification Sheet (June 2022)

Page 2

"Max FAST Cache": Shows the maximum FAST Cache capacity. The total cache is the sum of this and the system DRAM.

The Dell UnityVSA (Virtual Storage Appliance) is a software-defined version of the Unity XT platform that runs as a virtual machine. It provides core data services and connectivity options suitable for virtual environments. It fully supports block access over IP networks using the iSCSI protocol. Additionally, it includes native asynchronous replication capabilities, allowing data from file systems and LUNs to be replicated to another UnityVSA or a physical Unity XT array for disaster recovery purposes.

A. NVMe Connectivity is a hardware-level feature for high-performance flash access that is not available in the software-only, virtualized UnityVSA platform.

D. FC (Fibre Channel) Connectivity requires dedicated hardware (HBAs), which a virtual appliance like UnityVSA does not have. All its connectivity is through the hypervisor's virtual network interfaces.

E. Dynamic Pools are an advanced pooling technology available on physical Dell Unity XT hardware arrays to optimize performance and capacity; this feature is not supported on UnityVSA.

1. Dell UnityVSA Datasheet (dell-unity-vsa-datasheet.pdf). The datasheet lists "iSCSI" under supported protocols and "Native Asynchronous Block & File Replication" under Data Protection features. It does not list FC

NVMe

or Dynamic Pools.

2. Dell White Paper: "Dell Unity: Introduction to the Unity Platform" (H15093.7). Page 10

Table 2 "Dell Unity models". This table compares the physical and virtual models

showing that UnityVSA supports iSCSI and Replication but lacks hardware-dependent features like FC.

To prevent data corruption during a LUN snapshot restore, administrators must first safely halt operations by quiescing host I/O. Next, the host is disconnected from the production LUN, and any hosts currently attached to the LUN's snapshots must be detached to remove active dependencies. Once these safety prerequisites are met, the administrator selects the restore operation. Before overwriting the active LUN, the storage system automatically generates a backup snapshot of the current LUN state as a fail-safe mechanism against accidental data loss. Finally, the system executes the operation, and the LUN is fully restored to the data state captured in the chosen snapshot.

Dell Technologies. (2021). Dell EMC Unity: Snapshots and Thin Clones - A Detailed Review. Dell EMC Engineering White Paper (Document ID: H15089). Section: "Snapshot Restore Operations," pp. 18-20. This document explicitly outlines the prerequisite sequence of quiescing I/O, disconnecting hosts, and detaching snapshots before initiating a restore, as well as the system's automatic fail-safe snapshot creation.

Dell Technologies Support. Dell Unity Family Data Protection Guide. Chapter: "Managing Snapshots," Section: "Restore a block storage resource from a snapshot." This vendor documentation details the step-by-step UI and system workflow for LUN restoration corresponding exactly to the sequence provided.

Provisioning SMB NAS storage follows a strict hierarchical dependency.

1. First, physical hard drives must be aggregated into logical storage pools to provide underlying capacity.
2. Second, a NAS server must be instantiated and assigned to an existing pool to manage network interfaces and file protocols (SMB/NFS).
3. Third, file systems and their respective shares are created within the NAS server's namespace, utilizing the supported protocol.
4. Finally, the end-user or host client maps the shared file system (e.g., via mapping a network drive in Windows) over the network to access the provisioned storage.

Dell EMC Unity: NAS Capabilities - A Detailed Review: Section "NAS Server Provisioning" and "File System Provisioning." This document officially details that a storage pool is a prerequisite for a NAS Server, which in turn is a prerequisite for creating file systems and SMB shares.

Information Storage and Management (ISM) v4/v5 (Dell EMC Education Services): Chapter on "File-Based Storage System Components and Architecture." The official courseware outlines the standard NAS provisioning lifecycle from physical disk grouping (pools) to logical server creation, share creation, and finally client-side mounting/mapping.

The Dell Unity XT system stores all schedule times in Coordinated Universal Time (UTC). The Time Zone setting in Unisphere is purely for display purposes, translating the UTC time to the selected local time for the administrator. When the time zone is changed, it does not alter the underlying UTC time at which existing schedules are set to run. Therefore, a schedule created at 8 PM in a previous time zone will continue to run at that same absolute UTC time, which will be displayed as a different local time in the new time zone.

A. This statement is unclearly worded and does not accurately describe the system's behavior with UTC-based scheduling.

B. The system time (UTC) is likely correct; the issue is the user's expectation of how a display time zone change affects pre-existing schedules.

D. A restart of the management server is not required for a time zone setting change to be applied for display purposes.

Dell Unity Family Unisphere Administration Guide (Version 5.3)

"Date and Time" section (Page 288): "The system time is set to Coordinated Universal Time (UTC) and cannot be changed. You can

however

select a time zone for displaying the time in Unisphere." This confirms schedules are based on a fixed UTC time

and the setting only affects the display.

The question contains a common point of confusion between Dynamic Pools and Traditional Pools. For Dynamic Pools, the underlying structures are Drive Partnership Groups (DPGs), and the maximum width (size) of a single DPG is 16 drives (e.g., 14+2 for RAID 6). However, for Traditional Pools, the maximum number of drives in a RAID 6 group is 32. Given the options, the question is likely flawed and incorrectly refers to a Dynamic Pool when intending to ask about the limit for a Traditional Pool's RAID 6 group.

A. 64 drives: This number does not correspond to a maximum RAID group or partnership group size for either Traditional or Dynamic pools on Dell Unity XT.

B. 84 drives: This is not a valid maximum group size for any pool or RAID type on the Dell Unity XT platform.

C. 96 drives: This is not a valid maximum group size for any pool or RAID type on the Dell Unity XT platform.

1. Dell Unity: Best Practices Guide (Technical White Paper)

Page 11: "For traditional pools

the maximum number of drives in a RAID 5 private RAID group is 16

and the maximum for a RAID 6 private RAID group is 32."

2. Dell Unity: Dynamic Pools (White Paper)

Page 11

Table 2: This table shows the available RAID widths for Drive Partnership Groups in Dynamic Pools

with the maximum being 16 drives for a 14+2 RAID 6 configuration.

For a VMware vCenter server to recognize and manage a Dell Unity XT array for vSphere Virtual Volumes (vVols), the array's VASA (vSphere APIs for Storage Awareness) provider must be registered with the vCenter. This registration establishes the communication channel that allows vCenter to discover the array's storage capabilities, create protocol endpoints, and provision vVol datastores. Without this crucial step, vCenter is unaware of the Unity system's vVol capabilities, making datastore creation impossible.

A. While host connectivity is required for data access, VASA registration is the specific prerequisite for vCenter to even begin the vVol datastore provisioning process.

B. Capability Profiles are used within vSphere Storage Policies to manage vVol placement after the datastore is created, not as a prerequisite for its creation.

D. This is too generic. The specific action required is registering the VASA provider, which is a specialized function, not just a general API registration.

- Dell EMC Unity: Virtualization Integration

White Paper (April 2020)

Page 13

"vSphere Virtual Volumes": "To enable vVols

the storage provider must be registered in vCenter. This is done by navigating to the vCenter Server in Unisphere

selecting the vCenter

and clicking the Register Storage Provider button."

- Dell Unity Family Unisphere Command Line Interface User Guide

Version 5.1

Page 271

/remote/vcenter/vasa create: "Registers a VASA provider with a vCenter."