Free Practice Questions for EMC D-PVM-OE-01 Exam

Step by Step Comprehensive Detailed Explanation:

In an SRDF (Symmetrix Remote Data Facility) disaster recovery scenario where production has been switched to the R2 devices at the target site, theResumeoperation allows the primary hosts to regain access to the R1 devices without waiting for a full data transfer from the R2 devices.

Here's how it works:

R1 Access:The Resume operation makes the R1 devices (at the primary site) accessible to the primary hosts.

Background Synchronization:While the hosts access and modify data on the R1 devices, SRDF continues to synchronize the changes from the R2 devices (at the target site) in the background. This ensures that the R1 devices are gradually updated with any changes that occurred on the R2 devices during the failover.

This approach minimizes downtime and allows for a quicker return to the primary site without waiting for a lengthy synchronization process to complete before granting host access.

Why other options are incorrect:

A. Update:This operation copies changes from R2 to R1, but it doesn't necessarily grant immediate host access to R1.

B. Fallback:This is a more comprehensive process that involves reversing replication direction and fully restoring the primary site as the production environment.

C. Failover:This operation switches production to the R2 devices, not the R1 devices.

References and documents of Dell's public documentation for PowerMax Operate v.2:

Dell Solutions Enabler 10.0.0 SRDF Family CLI User Guide:This guide provides detailed information about SRDF commands and operations, including the symrdf resume command. You can find this document on the Dell Support website by searching for "Solutions Enabler SRDF Family CLI User Guide."

Dell PowerMax Family: Essentials and Best Practices Guide:This guide offers a comprehensive overview of SRDF and its functionalities, including disaster recovery scenarios and the use of the "Resume" operation.

Step by Step Comprehensive Detailed Explanation:

Solutions Enabler (SE) 10 introduces some changes to the output format of certain commands for better clarity and consistency. When querying a PowerMax 2000 (which is based on older VMAX architecture) using symcfg list -dir, you might encounter differences in the output compared to previous SE versions.

To ensure backward compatibility and see the output in the familiar format, you need to use the -mode v9x argument. This tells SE 10 to display the output in the style of SE 9.x, which is compatible with the PowerMax 2000.

Why other options are incorrect:

B. Look for CPU instead of Cores as these have been rebranded...:While there might be terminology changes, this is not the primary reason for the output difference.

C. Specify the full 12-digit serial number with -sid so SE 10 understands...:The serial number is not directly related to the output format.

D. Use syraconfigure -version -dir as in SE 10 support for outputs...:The syraconfigure command is not the correct command for this purpose.

References and documents of Dell's public documentation for PowerMax Operate v.2:

Dell Solutions Enabler 10.0.0 CLI User Guide:This guide provides detailed information about the symcfg command and its options, including the -mode argument for backward compatibility. You can find this document on the Dell Support website by searching for "Solutions Enabler CLI User Guide."

Step by Step Comprehensive Detailed Explanation:

The Workload Planner in Unisphere for PowerMax helps you analyze and predict the performance impact of adding new workloads to your storage array. It uses sophisticated algorithms to calculate howthe addition of a new workload will affect the existing workloads and whether it will violate any service level objectives (SLOs).

To determine if a Storage Group workload is stable, the Planner considers two key calculated values:

Read Response Time:The predicted read response time of the Storage Group after the new workload is added.

Write Response Time:The predicted write response time of the Storage Group after the new workload is added.

The Planner compares these calculated values against the service level (SL) defined for the Storage Group. Ifboththe calculated read and write response times fall within the defined SL response time, the Planner considers the workload to be stable. This means that the new workload can be added without negatively impacting the performance of the existing workloads or violating the SLOs.

Why other options are incorrect:

A. One of the calculated values is within 10-20% of the SL-defined response time:Both read and write response times must be within the defined SL, not just one.

B. Both calculated values are within a 10-15% threshold of the SL-defined response time:The threshold is not fixed at 10-15%. The calculated values must be within the actual SL-defined response time.

C. One of the calculated values remains within the SL-defined response time:Again, both read and write response times need to be within the defined SL.

References and documents of Dell's public documentation for PowerMax Operate v.2:

Dell Unisphere for PowerMax 10.0.0 Online Help:The online help for Unisphere provides detailed information about the Workload Planner feature, including how it calculates and analyzes workload stability. You can access this help within Unisphere itself or on the Dell Support website.

Dell PowerMax Family: Essentials and Best Practices Guide:This guide may offer general information about performance management and workload planning in PowerMax, providing context for understanding the Workload Planner's functionality.

Step by Step Comprehensive Detailed Explanation:

Dell PowerMax storage arrays utilize different device types for various purposes. Solutions Enabler (SYMCLI) and Unisphere for PowerMax are management tools that can interact with these device types. Here's a breakdown:

SRDF Thin Devices (RDF1 or RDF2):These devices are specifically used for SRDF (Symmetrix Remote Data Facility) replication. RDF1 devices represent the local copy of data in an SRDFrelationship, while RDF2 devices represent the remote copy. Both Solutions Enabler and Unisphere can manage these devices to configure and monitor SRDF replication.

Internal Thin Devices (Int+TDEV):These are thin provisioned devices that reside within the PowerMax storage array. They are used for general storage purposes and can be managed by both Solutions Enabler and Unisphere for tasks like provisioning, allocating capacity, and monitoring performance.

Thin Devices (TDEV):This is a general term for thin provisioned devices in PowerMax. Thin provisioning allows for efficient storage utilization by allocating capacity on demand.1Both Solutions Enabler and Unisphere can manage these devices.  

Why other options are incorrect:

B. Thin BCV Devices (BCV+TDEV):BCV (Business Continuance Volume) devices are used for creating point-in-time copies for disaster recovery. While Solutions Enabler can manage BCV devices, Unisphere for PowerMax has limited functionality for managing them directly.

D. Data Devices (TDATs):TDATs are physical devices within the PowerMax array. While Solutions Enabler can interact with TDATs at a lower level, Unisphere for PowerMax primarily focuses on managing logical devices and storage groups.

References and documents of Dell's public documentation for PowerMax Operate v.2:

Dell PowerMax Family: Essentials and Best Practices Guide:This guide provides an overview of PowerMax devices and their management. It mentions the different device types and how they are used in the PowerMax environment.

Dell Solutions Enabler 10.0.0 CLI User Guide:This guide provides detailed information about Solutions Enabler commands for managing various device types, including SRDF devices, thin devices, and internal devices.

Dell Unisphere for PowerMax 10.0.0 Online Help:The online help documentation for Unisphere for PowerMax explains how to manage different device types through the graphical user interface, including provisioning, monitoring, and configuring storage.

Step by Step Comprehensive Detailed Explanation:

In SRDF (Symmetrix Remote Data Facility), a "Restore" operation is used to resynchronize the source (R1) and target (R2) devices after a situation where the target device might have been modified independently. This typically occurs after a failover scenario where the target device becomes the primary and undergoes changes.

During an SRDF Restore operation:

R2 Changes Discarded:Any changes made to the target (R2) device since the last synchronization are discarded.

R1 Changes Propagated:The current data on the source (R1) device is copied over to the target (R2), overwriting any existing data on the target.

This effectively restores the target device to a state consistent with the source device, ensuring data integrity and consistency.

Why other options are incorrect:

B. Resumes normal SRDF mirroring and host access:While a Restore operation can be part of the failback process, it's not the only step involved. Failback might involve additional actions like reversing replication direction and restoring host access.  

C. Changes made to the R2 are propagated to the R1. Changes made to the R1 are discarded:This describes an "Update" operation, not a "Restore."

D. Enables access to both the R1 and R2 devices for their hosts:This describes a "Split" operation, where both devices are made accessible independently.

References and documents of Dell's public documentation for PowerMax Operate v.2:

Dell Solutions Enabler 10.0.0 SRDF Family CLI User Guide:This guide provides detailed information about SRDF commands and operations, including the symrdf restore command. You can find this document on the Dell Support website by searching for "Solutions Enabler SRDF Family CLI User Guide."

Dell PowerMax Family: Essentials and Best Practices Guide:This guide offers a comprehensive overview of SRDF and its functionalities, including disaster recovery scenarios and the use of the "Restore" operation.