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

The service task that the administrator should perform to fix the issue with minimal impact is Restart Management Software. This service task restarts the management software on both storage processors without affecting the data services or the host I/O. This can resolve the communication issues between Unisphere and the storage system. Reinitialize, Enable SSH, and Reboot Storage Processor are service tasks that have more impact and risk than Restart Management Software.

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.

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.

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.

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.

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.