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

• Question 21:

  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

  Correct Answer: BC

  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 22:

  A deployment engineer has changed theSchedule Time Zoneunder the Settings menu. However, existing snapshots schedules continue to run at the previously configured time.

  Why is this occurring?

  A. Existing snapshot schedules cannot be updated to the same absolute time.

  B. The Unity system time is not set correctly and must be updated under system settings.

  C. Existing snapshot schedules are not updated to the same absolute time when the time zone is changed.

  D. The Unity management server was not restarted before time zone changes took effect.

  Correct Answer: C

  When the Schedule Time Zone is changed under the Settings menu, it only affects the display of the time zone and the creation of new snapshot schedules. Existing snapshot schedules are not automatically adjusted to the new time zone, and will continue to run at the same absolute time as before. For example, if a snapshot schedule was created to run every day at 10:00 AM inGMT+1, and the Schedule Time Zone was changed to GMT+2, the snapshot schedule will still run at 10:00 AM in GMT+1, which is

  11:00 AM in GMT+2. To update the existing snapshot schedules to the new time zone, the administrator must edit each schedule manually and change the start time accordingly. References: Dell EMC Unity: Snapshots and Thin Clones1, page 16.

• Question 23:

  What is a characteristic of FAST VP?

  A. Fast VP data relocation runs in the background at all times once it is enabled.

  B. Fast VP optimizes data replacement by moving 1 GB slices between disk tiers.

  C. Users can set the Fast VP data relocation rate.

  D. Users can enable or disable FAST VP at the LUN level.

  Correct Answer: C

  FAST VP (Fully Automated Storage Tiering for Virtual Pools) is a feature that automatically moves data within a storage pool based on the performance requirements and access patterns of the data. FAST VP data relocation runs in the background according to a user-defined schedule and rate. The schedule determines when the data relocation starts and ends, and the rate determines how much system resources are used for the data relocation. Users can set the Fast VP data relocation rate to High, Medium, Low, or None. High means that the data relocation has the highest priority and uses the most system resources, while None means that the data relocation is disabled. Fast VP data relocation does not run at all times, but only during the scheduled window. Fast VP optimizes data placement by moving 256 MB slices between disk tiers, not 1 GB slices. Users cannot enable or disable FAST VP at the LUN level, but only at the storage pool level. References: [Dell EMC Unity: FAST Technology Overview], [Dell EMC Unity: Storage Pools and RAID Groups]

• Question 24:

  What is a characteristic of Host Groups?

  A. Access to block storage resources must be set before adding hosts to a host group.

  B. Block storage resources addedlo a host group are accessible to all the member hosts

  C. Hosts added to a host group must not have mapped block storage resources.

  D. Block storage resources attached to one of the member hosts are accessible to the entire host group.

  Correct Answer: B

  A characteristic of Host Groups is that block storage resources added to a host group are accessible to all the member hosts. A Host Group is a logical grouping of hosts that share the same access permissions and settings for block storage

  resources. By adding block storage resources to a host group, the user can simplify the management and allocation of storage for multiple hosts. Access to block storage resources does not need to be set before adding hosts to a host group,

  as the access permissions can be modified later. Hosts added to a host group can have mapped block storage resources, as long as they are not in conflict with the host group resources. Block storage resources attached to one of the

  member hosts are not accessible to the entire host group, unless they are also added to the host group.

  References: [Dell EMC Unity: Host Configuration], [Dell EMC Unity: Block Storage Provisioning]

• Question 25:

  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.

  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

• Question 26:

  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

  Correct Answer: B

  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 27:

  A storage administrator has a Dell Unity XT 480 system with one pool of flash drives, 192 GB of RAM, and 1.2 TB of FAST Cache.

  What is the total cache availability for caching the flash drives?

  A. 3.2 TB

  B. 1.39 TB

  C. 3.58 TB

  D. I6.0 TB

  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]

• Question 28:

  What is the maximum number of drives on a traditional RAID Group?

  A. 64 drives

  B. 16 drives

  C. 8 drives

  D. 32 drives

  Correct Answer: B

• Question 29:

  What is the maximum size of a drive partnership group when expanding a Dynamic Pool?

  A. 64 drives

  B. 84 drives

  C. 96 drives

  D. 32 drives

  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.

• Question 30:

  Which two actions are recommended according to best practices when connecting iSCSI host to a Dell Unity XT system? (Choose two.)

  A. Manually register host on storage array.

  B. Use standard NIC for iSCSI.

  C. Interfaces should be on separate subnets.

  D. Use private network for iSCSI interfaces.

  Correct Answer: CD

  Two actions that are recommended according to best practices when connecting iSCSI host to a Dell Unity XT system are to ensure that the interfaces are on separate subnets and to use a private network for iSCSI interfaces. These actions can improve the performance, security, and availability of the iSCSI network. Having interfaces on separate subnets can prevent broadcast storms, reduce network congestion, and enable multipathing. Using a private network for iSCSI interfaces can isolate the iSCSI traffic from other network traffic, reduce the risk of interference or attacks, and simplify the network configuration. Manually registering host on storage array and using standard NIC for iSCSI are not recommended actions, as they can introduce errors, inefficiencies, and limitations. References: [Dell EMC Unity: iSCSI Configuration], [Dell EMC Unity: Best Practices Guide]