Dell D-UN-DY-23 Online Practice Questions and Exam Preparation

Dell D-UN-DY-23 Online Questions & Answers

• Question 1:

  What is the result of enabling Data Reduction on a LUN in a consistency group containing three LUNs?

  A. Any writes to the LUN will go through the Data Reduction logic.
  B. Data Reduction and Advanced Deduplication will be enabled on all LUNs.
  C. Data Reduction will be enabled on all LUNs is the consistency group.
  D. All writes to all consistency group LUNs will go through the Data Reduction logic.
  D. All writes to all consistency group LUNs will go through the Data Reduction logic.

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  Explanation/Reference:

  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

• Question 2:

  A company needs to expand their dynamic pool by 10 TB. The current dynamic pool consists of 63 7.6 TB SSD drives that are configured for RAID 5 (12+1).

  What is the minimum number of drives needed for the pool expansion?

  A. 1
  B. 15
  C. 13
  D. 2
  C. 13

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  Explanation/Reference:

  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.

• Question 3:

  A storage administrator recently disabled the Advanced Deduplication on a LUN.

  Which Dell Unity XT action can be used to remove the Advanced Deduplication savings from LUN?

  A. Unmask the LUNfrom host.
  B. Perform Local LUN Move.
  C. Chanqe Tierinq Policy to Auto-Tier.
  D. Disable the Data Reduction.
  B. Perform Local LUN Move.

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  Explanation/Reference:

  When Advanced Deduplication is disabled on a LUN, the existing data that was deduplicated remains in its reduced state, and only new data written to the LUN is not deduplicated. To remove the Advanced Deduplication savings from the LUN, the administrator must perform a Local LUN Move operation, which copies the data from the source LUN to a destination LUN without deduplication. The destination LUN must have Advanced Deduplication disabled, and must be in the same storage pool as the source LUN. After the Local LUN Move is completed, the source LUN can be deleted and the destination LUN can be renamed as the original LUN. References: Dell Unity: Data Reduction2, page 9.

• Question 4:

  A storage engineer must grant access of a Dell Unity XT provisioned NFS datastore to ESXi-1.dell.local. The NAS server used to create the datastore is configured for NFSv4 protocol with Kerberos NFS owner authentication.

  Which permission level is required for the ESXi host?

  A. Read/write
  B. Read-only
  C. Read/write, enable Root
  C. Read/write, enable Root

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  Explanation/Reference:

  To grant access of a Dell Unity XT provisioned NFS datastore to an ESXi host, the permission level required for the host depends on the NFS protocol and authentication method used by the NAS server. For NFSv4 with Kerberos NFS owner

  authentication, the ESXi host must have the Read/write, enable Root permission level. This allows the ESXi host to read and write data to the datastore, as well as perform administrative tasks such as creating and deleting virtual machines.

  The Read/write permission level alone is not sufficient, as it does not allow the ESXihost to perform root- level operations on the datastore. The Read-only permission level only allows the ESXi host to read data from the datastore, but not

  write or modify it. References: Dell EMC Unity:

  Configuring hosts to access NFS1, page 9.

• Question 5:

  Which is the preferred FC Port for synchronous replication for a Dell Unity XT 380 system?

  A. Fibre Channel Port 0 of I/O module 0
  B. Fibre Channel Port 4 of SPA and SPB www*
  C. Port 0 of I/O module 1
  D. Port 1 of I/O module 0
  B. Fibre Channel Port 4 of SPA and SPB www*

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  Explanation/Reference:

  The preferred FC Port for synchronous replication for a Dell Unity XT 380 system is Fibre Channel Port 4 of SPA and SPB. This port is dedicated for synchronous replication traffic and has the highest priority and bandwidth allocation. Synchronous replication is a method of replicating data between two Dell Unity systems with zero recovery point objective (RPO). It requires a low-latency and high-bandwidth network connection between the source and destination systems. References: [Dell EMC Unity: Replication Technologies], [Dell EMC Unity: Hardware Information Guide]

• Question 6:

  What are two prerequisites when creating host configuration for NFS client? (Choose two.)

  A. Tenant information
  B. Network Address
  C. Subnet access
  D. Hostname
  B. Network Address
  D. Hostname

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  Explanation/Reference:

  Host configuration is the process of defining the host properties and access permissions for a host that connects to the Dell Unity XT system. For NFS clients, the host configuration requires two prerequisites:

  Network Address: The network address is the IP address or the subnet mask of the NFS client that identifies the host on the network. The network address is used to register the host on the Dell Unity XT system and to grant access to the

  NFS filesystems.

  Hostname: The hostname is the name of the NFS client that is resolved by the DNS server or the local hosts file. The hostname is used to display the host information on the Unisphere UI and to enable host monitoring and alerting.

  References:

  Dell EMC Unity: Host Configuration

  Dell EMC Unity: File System Configuration and Management

• Question 7:

  Which are two features of the Dell UnityVSA? (Choose two.)

  A. NVMe Connectivity
  B. iSCSI Connectivity
  C. Asynchronous Replication
  D. FC Connectivity
  E. Dynamic Pools
  B. iSCSI Connectivity
  C. Asynchronous Replication

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  Explanation/Reference:

  The Dell UnityVSA is a software-defined storage solution that runs the Dell Unity operating environment on a VMware ESXi server. The Dell UnityVSA provides the same features and functions as the Dell Unity hardware platform, such as

  block and file storage, snapshots, thin clones, data reduction, replication, and encryption. Some of the features of the Dell UnityVSA are:

  iSCSI Connectivity: The Dell UnityVSA supports iSCSI connectivity for block storage access. The iSCSI protocol enables hosts to communicate with the DellUnityVSA over an IP network and access LUNs as SCSI devices. The Dell UnityVSA

  can support up to 64 iSCSI interfaces and up to 256 iSCSI sessions per interface.

  Asynchronous Replication: The Dell UnityVSA supports asynchronous replication for block and file storage. Asynchronous replication is a feature that copies data from a source storage resource to a destination storage resource over a

  network at scheduled intervals. Asynchronous replication can be used for disaster recovery, data migration, or backup purposes. The Dell UnityVSA can support up to 256 replication sessions per system.

  References:

  Dell EMC Unity: Introduction to the Platform

  Dell EMC Unity: Deploying VMware vSphere with Dell EMC UnityVSA Dell EMC Unity: Configuring Hosts to Access Block Storage Dell EMC Unity: Replication Technologies

• Question 8:

  A company has an ESXi host installed with FC HBAs that is connected to a Dell Unity XT storage array. A 500 GB LUN is provisioned to this host from the Unity array and is in production. The VMware administrator has configured a new vSwitch with the NICs on the server intended for iSCSI traffic. The storage administrator is asked to configure software iSCSI and provision a new 1 TB LUN from the storage array using iSCSI.

  What is a consideration when satisfying this request?

  A. Two iSCSI target interfaces must be configured with IP addresses from separate subnets.
  B. Any single host should connect to any single array using one protocol only.
  C. A connection must be established between the host iSCSI initiators and Unity iSCSI targets before provisioning the new LUN.
  B. Any single host should connect to any single array using one protocol only.

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  Explanation/Reference:

  Mixing FC and iSCSI protocols for the same host and array is not supported by Dell EMC Unity. This can cause issues with multipathing, failover, and performance. The best practice is to use one protocol per host and array pair. If the host needs to access both FC and iSCSI LUNs from different arrays, then separate vSwitches and port groups should be used for each protocol. References: Dell EMC Unity: Best Practices Guide1, page 19.

• Question 9:

  What does the Dell Unity XT system do after a NAS server starts outbound traffic to an external service?

  A. Uses the active production interface
  B. Creates an active interface buffer cache in DRAM
  C. Selects interfaces that are based on advance static routes
  D. Uses Packet Reflect for outbound communication
  D. Uses Packet Reflect for outbound communication

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  Explanation/Reference:

  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

• Question 10:

  Multiple I/O modules must be installed in Dell Unity XT 680 storage.

  Which module must be installed in slot 0?

  A. 4-Port 25 Gbps Ethernet
  B. 4-Port 16 Gb Fibre Channel
  C. 4-Port 10 Gbps Ethernet
  D. 12 Gb/s SAS back-end
  D. 12 Gb/s SAS back-end

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  Explanation/Reference:

  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