EMC D-UN-DY-23 Dell Unity Deploy 2023 Exam Exam Practice Test

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]

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.

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]

If the time difference between the current system (UTC) time and the NTP server time is too large (approximately 17 minutes), the user cannot configure an NTP server during initial configuration. The user will need to adjust the time while in “Set time manually” mode before changing to “Enable NTP synchronization”. This is to avoid potential issues with data replication, snapshots, and audit logs that rely on accurate time stamps. References: Dell EMC Unity: How to change System Time from ‘Set time manually’ option to NTP2, page 1.

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

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 correct sequence of steps to provision storage for SMB NAS clients is:

• Group hard drives into storage pools. This allows you to create a pool of storage resources that can be allocated to different types of storage objects, such as NAS servers, file systems, and LUNs.You can create different pools based on the performance and capacity requirements of your applications1
• Create a NAS server for an existing pool. A NAS server is a logical entity that provides file-level access to clients using SMB, NFS, or FTP/SFTP protocols. You need to create a NAS server before you can create file systems and shares.You can specify the pool, network settings, domain membership, and other properties for the NAS server2
• Create file systems and file system shares based on the supported NAS protocol. A file system is a logical container that stores files and folders on a NAS server. A file system share is a logical representation of a file system that can be accessed by clients using a specific protocol. For SMB NAS clients, you need to create SMB file system shares that support the SMB protocol.You can configure the share name, permissions, access policies, and other settings for the SMB share3
• Map the shared file system to the client. This allows the client to access the files and folders on the SMB share using a drive letter or a UNC path.You can use the Windows Explorer or the net use command to map the shared file system to the client4

 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.

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

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]