D-UN-DY-23 Online Practice Questions and Answers

Correct Answer: D

Packet Reflect is a feature that enables the Dell Unity XT system to use the same interface for outbound communication that was used for inbound communication. This feature is useful when the Dell Unity XT system needs to initiate outbound traffic to an external service, such as DNS, NTP, LDAP, or SMTP. By using Packet Reflect, the Dell Unity XT system can avoid routing issues, firewall restrictions, or network address translation problems that may occur when using a different interface for outbound communication. When a NAS server starts outbound traffic to an external service, the Dell Unity XT system uses Packet Reflect to send the packets through the same interface that received the packets from the external service. Therefore, the correct answer is D. Uses Packet Reflect for outbound communication. References: Dell EMC Unity: NAS Capabilities Dell EMC Unity: Unisphere Overview

Correct Answer: C

A benefit of using vVols is that individual VMs on a datastore can be snapped. vVols are virtual volumes that are stored on a storage array and managed by vSphere. They enable granular control and management of VM storage. With vVols,

each VM has its own set of virtual disks that are mapped to corresponding storage objects on the array. This allows the array to perform snapshot operations on individual VMs without affecting other VMs on the same datastore.

References: [Dell EMC Unity: VMware vSphere Virtual Volumes (vVols) Implementation]

Correct Answer: CE

A Host Group is a logical grouping of hosts that share the same access permissions to storage objects, such as LUNs, VMFS Datastores, or NFS Filesystems. By configuring a Host Group, an administrator can simplify the management of multiple hosts and ensure consistent access to the storage resources. Some of the benefits of using a Host Group are: Provides multiple hosts access to the same VMFS Datastores: A VMFS Datastore is a block-based storage object that is formatted with the VMware File System (VMFS) and used to store virtual machine files. A VMFS Datastore can be shared by multiple hosts that are part of a VMware cluster. By adding these hosts to a Host Group and assigning the VMFS Datastore to the Host Group, the administrator can ensure that all the hosts have the same access permissions and can access the virtual machines on the Datastore. Provides multiple hosts access to the same LUNs: A LUN is a block-based storage object that is presented to a host as a SCSI device. A LUN can be shared by multiple hosts that have the same operating system and use a cluster-aware file system. By adding these hosts to a Host Group and assigning the LUN to the Host Group, the administrator can ensure that all the hosts have the same access permissions and can access the data on the LUN. References: Dell EMC Unity: Host Configuration Dell EMC Unity: VMware ESXi Hosts and Clusters

Correct Answer: A

On a Dell Unity XT file system asynchronous replication session, four system Snapshots are required to support replication. Two system Snapshots are created on the source file system, and two system Snapshots are created on the destination file system. The source system Snapshots are used to track the changes that need to be replicated, and the destination system Snapshots are used to apply the changes and maintain a consistent point-in-time copy of the source data. The system Snapshots are automatically created and managed by the replication engine and are not visible to the user. References: [Dell EMC Unity: Replication Technologies], [Dell EMC Unity: File System Configuration]

Correct Answer: A

The purpose of a Proxy NAS server is to access snapshot replicas on the destination side of a replicated file resource. A Proxy NAS server is a temporary NAS server that is created on the destination system to mount a snapshot replica of a replicated file system. This allows the user to access the data on the snapshot replica for testing, recovery, or other purposes. A Proxy NAS server does not increase performance or security of production NAS servers, nor does it access snapshots for testing production NAS servers.

Correct Answer: A

The service task that the administrator should perform to fix the issue with minimal impact is Restart Management Software. This service task restarts the management software on both storage processors without affecting the data services or the host I/O. This can resolve the communication issues between Unisphere and the storage system. Reinitialize, Enable SSH, and Reboot Storage Processor are service tasks that have more impact and risk than Restart Management Software. References: [Dell EMC Unity: Unisphere Overview], [Dell EMC Unity: Service Tasks]

Correct Answer: C

The Unity 380/380F system supports two types of I/O modules: 12 Gb/s SAS back-end and 10 GbE Base-T front-end. The 12 Gb/s SAS back-end module provides connectivity to the disk drives and expansion enclosures, while the 10 GbE Base-T front- end module provides network connectivity to the hosts and clients. The Unity 380/380F system has four I/O module slots, two for each SP. The 12 Gb/s SAS back-end module must be installed in slot 0 of each SP, and the 10 GbE Base-T front-end module can be installed in slot 1 of each SP. Therefore, the correct answer is C References: Dell EMC Unity: Hardware Information Guide Dell EMC Unity: Installation Guide

Correct Answer: C

To expand a dynamic pool, the number of drives added must be equal to or greater than the stripe width of the pool. The stripe width is the number of data drives plus the number of parity drives in a RAID group. In this case, the stripe width is 12 + 1 =

13. Therefore, the minimum number of drives needed for the pool expansion is

13. References: Dell EMC Unity: Dynamic Pools Technical White Paper1, page 8.

Correct Answer: C

To apply the management IP from the vSphere UnityVSA console, the system administrator must use the svc_initial_config command. This command allows the user to configure the initial network settings for the UnityVSA, such as the management IP address, subnet mask, gateway, and DNS servers. The svc_ipmi command is used to configure the IPMI settings for the UnityVSA, such as the IPMI IP address, username, and password. The svc_change_hw_config command is used to change the hardware configuration of the UnityVSA, such as the number of CPU cores, memory size, and disk size. The svc_inject command is used to inject faults into the UnityVSA for testing purposes. References: [Dell EMC UnityVSA Installation Guide], [Dell EMC UnityVSA Command Line Interface Reference Guide]

Correct Answer: B

A LUN is a logical unit of storage that is presented to a host as a SCSI device. A LUN is composed of one or more RAID extents, which are the smallest units of storage that can be allocated to a LUN. A RAID extent is a slice of a RAID group that is used to store user data and parity information. The size of a RAID extent depends on the RAID type and the drive type of the RAID group. For example, a RAID 5 extent on a SAS drive is 128 MB, while a RAID 6 extent on a NL-SAS drive is 256 MB. The LUN is partitioned into slices that match the size of the RAID extents, and each slice is mapped to a RAID extent from a RAID group in the storage pool. The LUN slices are distributed across multiple RAID groups to improve performance and availability. References: Dell EMC Unity: Storage Pools and RAID Groups Dell EMC Unity: LUN Management

Correct Answer: D

Data Reduction is a feature that reduces the amount of physical storage space required to store user data on a LUN. Data Reduction is enabled at the LUN level and applies to all the data in the LUN, including snapshots and thin clones. Data Reduction consists of two components: compression and deduplication. Compression reduces the size of data blocks by removing redundant information, while deduplication eliminates duplicate blocks across the LUN. When Data Reduction is enabled on a LUN, all writes to the LUN will go through the Data Reduction logic before being written to the storage pool. If the LUN is part of a consistency group, Data Reduction will be enabled on all the LUNs in the consistency group, and all writes to any LUN in the group will go through the Data Reduction logic. This ensures that the data in the consistency group is consistent and protected by the same Data Reduction settings. References: Dell EMC Unity: Data Reduction Overview Dell EMC Unity: Data Reduction Configuration and Best Practices

Correct Answer: C

The total cache availability for caching the flash drives on a Dell Unity XT 480 system with one pool of flash drives, 192 GB of RAM, and 1.2 TB of FAST Cache is 3.58 TB. This is calculated by adding the system memory (RAM), the FAST Cache, and the pool cache. The system memory is 192 GB, which is equivalent to 0.18 TB. The FAST Cache is 1.2 TB, which is a dedicated cache for the flash drives. The pool cache is 2.2 TB, which is a portion of the flash drives that is reserved for caching the pool data. Therefore, the total cache availability is 0.18 + 1.2 + 2.2 = 3.58 TB. References: [Dell EMC Unity: Performance Metrics], [Dell EMC Unity: FAST Cache Overview]

Correct Answer: D

A drive partnership group is a collection of drives of the same drive type that have been combined into a hidden dynamic pool object. Each drive within a dynamic pool can only be part of a single drive partnership group, and a drive will never change the drive partnership group. The maximum size of a drive partnership group is 32 drives, regardless of the drive type or size. When expanding a dynamic pool, the system will automatically create new drive partnership groups as needed, and distribute the drives evenly across the groups. The number of drive partnership groups in a dynamic pool is equal to the number of drives divided by 32, rounded up to the nearest integer. References: Dell Unity: Dynamic Pools2, page 5.

Correct Answer: D

The Unity XT 680 system supports four types of I/O modules: 12 Gb/s SAS back-end, 4-Port 16 Gb Fibre Channel, 4-Port 25 Gbps Ethernet, and 4-Port 10 Gbps Ethernet. The 12 Gb/s SAS back-end module provides connectivity to the disk drives and expansion enclosures, while the other three types of modules provide network connectivity to the hosts and clients. The Unity XT 680 system has six I/O module slots, three for each SP. The 12 Gb/s SAS back-end module must be installed in slot 0 of each SP, and the other modules can be installed in slots 1 and 2 of each SP. Therefore, the correct answer is D. 12 Gb/s SAS back-end. References: Dell EMC Unity XT: Hardware Information Guide Dell EMC Unity XT: Installation Guide

Correct Answer: