EMC D-UN-DY-23 Dumps

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

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

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]

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.

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.

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

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

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.

To meet the requirements, the replication connection mode must be set to Both, which allows both synchronous and asynchronous replication sessions to be configured on the same connection. This way, block resources can use synchronous replication, which ensures zero data loss, and file resources can use asynchronous replication, which allows some data difference on the destination. Setting Unisphere resource filtering to All is not necessary, as it only affects the display of resources in the Unisphere GUI. Setting an RPO of 0 on the synchronous replication sessions is redundant, as synchronous replication always has an RPO of 0. Configuring the replication interfaces on the 4-port mezzanine card is not relevant, as it only affects the performance and availability of the replication network.

References: [Dell EMC Unity: Replication Technologies], [Dell EMC Unity: Unisphere Overview]

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]