DEE-1111 Exam Dumps - EMC Certification Questions and Answers

A company plans to implement SRDF/Star, which is a three-site replication solution that provides continuous data protection and disaster recovery capabilities. It is currently using SRDF/S between their two data centers, which are located within 200 kilometersand use synchronous replication. It is setting up a third data center and wants to have at least two identical copies of its data in case of a primary site failure. The third site can be located anywhere in the world and use asynchronous replication. The condition that is needed for the connection between the first two sites and the third site is that the link must be able to transport the delta set of the Recovery Point Objective (RPO) within the company’s Recovery Time Objective (RTO). The delta set is the amount of data that has changed since the last successful replication cycle. The RPO is the maximum acceptable amount of data loss measured in time. The RTO is the maximum acceptable amount of time to restore normal operations after a disaster. The link must have enough bandwidth and latency to ensure that the delta set can be transferred within the RTO without exceeding the RPO.

References:

• SRDF Star software uses and best practices
• SRDF/STAR
• Remote replication using SRDF

An application owner is experiencing performance issues for their application. Unisphere for PowerMax is showing the storage group is compliant with the current Service Level. This means that the performance issue is not caused by the storage system, but by some other factor in the environment, such as network congestion, host configuration, or application workload. One possible way to address the performance issue is to redistribute the application to other front-end host ports on different directors. This can help balance the workload across multiple paths and avoid potential bottlenecks or contention on a single port or director. Unisphere for PowerMax provides a Performance Plan feature that can analyze the current configuration and suggest optimal port allocation for each storage group based on historical data and best practices.

References:

• Understanding Performance Management
• Dell EMC PowerMaxOS Performance Guide

he %Busy and Balance KPIs are the most important indicators of the BE performance on a PowerMax array. The %Busy metric shows the percentage of time that a BE director is busy processing I/O requests. A high %Busy value may indicate that the BE director is overloaded and cannot keep up with the demand. The Balance metric shows the difference in %Busy between the two BE directors in a pair. A high Balance value may indicate that the workload is not evenly distributed across the pair, which can lead to performance degradation. By monitoring these two KPIs, a storage administrator can identify and troubleshoot any potential issues with the BE performance.

References:

• PowerMax Performance Troubleshooting with Unisphere - Run a real time trace at the system level

The NDM Updates feature should be used to complete the migration and address the client’s concern. The NDM Updates feature is designed to help automate the process of moving applications across arrays requiring a short application downtime. It allows application migration from a VMAX (5876) array to a VMAX3 (5977), VMAX All Flash (5978), or PowerMax (5978) array1. It supports pre-sync data between arrays and then schedule downtime to do the cutover1. References: Dell EMC PowerMax and VMAX: Non-Disruptive Migration Best Practices and Operational Guide

When vWitness and Array Witness options are deployed in the same operating environment simultaneously, SRDF/Metro favors the Witness option over the Array Witness option. This is because the Witness option provides a higher level of protection against split-brain scenarios and data loss than the Array Witness option. The Witness option uses a third-party server to monitor the health and connectivity of both SRDF/Metro arrays and to arbitrate in case of a failure. The Array Witness option uses a third array to store configuration information and to arbitrate in case of a failure. However, the Array Witness option does not monitor the health and connectivity of both SRDF/Metro arrays, and it requires manual intervention to resume SRDF/Metro replication after a failure.

 When maintenance tasks at the R1 data center require the array to be offline, a Swap operation should be executed on the Metro RDF pairs. This operation allows for a planned outage without affecting application I/O by swapping the roles of R1 and R2 devices.