D-UN-DY-23 Questions and Answers

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

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.

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

On a Dell Unity XT file system asynchronous replication session, four system Snapshots are required to support replication. Two system Snapshots are created on the source file system, and two system Snapshots are created on the destination file system. The source system Snapshots are used to track the changes that need to be replicated, and the destination system Snapshots are used to apply the changes and maintain a consistent point-in-time copy of the source data. The system Snapshots are automatically created and managed by the replication engine and are not visible to the user.

References: [Dell EMC Unity: Replication Technologies], [Dell EMC Unity: File System Configuration]

The maximum number of replicated NAS servers supported for the Dell Unity XT 380 series in an asynchronous replication is 126. This is the same as the maximum number of NAS servers supported for the Dell Unity XT 380 series in general. Asynchronous replication is a method of replicating data between two Dell Unity systems with a configurable recovery point objective (RPO). It allows the source system to continue normal operations without waiting for the destination system to acknowledge the completion of the replication.

References: [Dell EMC Unity: Replication Technologies], [Dell EMC Unity: NAS Capabilities]