D-UN-DY-23 Dell Unity Deploy 2023 Exam Questions and Answers

When deploying Dell UnityVSA OVA, the recommended disk format is Thick Provision Eager Zeroed, which allocates and zeroes out all the space for the virtual disks at the time of creation. This ensures better performance and avoids potential issues with thin provisioning on the underlying storage. Thin Provision and Thick Provision Lazy Zeroed are not recommended, as they may cause performance degradation and unexpected out-of-space errors.

References: [Dell EMC UnityVSA Installation Guide], [Dell EMC UnityVSA Best Practices Guide]

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]

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. 12 Gb/s SAS 10 GbE Base-T. References:

• Dell EMC Unity: Hardware Information Guide
• Dell EMC Unity: Installation Guide

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]

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

The maximum number of drives on a traditional RAID group depends on the RAID type and the drive type. For RAID 5 and RAID 6, the maximum number of drives is 16 for all drive types. For RAID 1/0, the maximum number of drives is 32 for SAS and NL-SAS drives, and 16 for SSD drives. References: Dell EMC Unity: Best Practices Guide2, page 17.

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]