Pass the EMC Proven Professional D-UN-DY-23 Questions and answers with ExamsMirror

Two ways to create an asynchronous replication session for a NAS server are to use NAS server properties and to use the NAS server wizard. Both methods allow the user to select a source NAS server and a destination NAS server, and configure the replication settings, such as the RPO, the replication schedule, and the replication mode. Creating a replication connection or a replication interface are not ways to create an asynchronous replication session for a NAS server, but rather prerequisites for enabling replication between two Dell Unity systems.

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

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 in GMT+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.

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

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.

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.

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.

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 snapshot option that is set automatically when a pool is configured is the Pool Automatic Deletion Policy. This option determines how the system handles the deletion of snapshots when the pool reaches a certain threshold of capacity utilization. The user can choose between three policies: Never Delete, Delete Oldest, or Delete Lowest Priority. The Total Pool Consumption and the Snapshot Pool Consumption are not snapshot options, but rather metrics that show the amount of pool space consumed by the pool data and the snapshots respectively.

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.