EMC Updated D-UN-DY-23 Exam Questions and Answers by subhan

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.

References: [Dell EMC Unity: iSCSI Configuration], [Dell EMC Unity: Best Practices Guide]

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]

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.

References: [Dell EMC Unity: Unisphere Overview], [Dell EMC Unity: Service Tasks]