DEE-1111 Exam Dumps - Expert - PowerMax and VMAX All Flash Solutions

 In a SRDF/Metro deployment in a clustered host configuration, when the RDF link state is partitioned and the R1 side has full read/write capability to the application, the R2 device also has full read/write capability to the application. With SRDF/Metro, both R1 and R2 devices may then appear as a single virtual device across the two SRDF paired arrays for host presentation. With both the R1 and R2 devices being accessible, the host or hosts (in the case of a cluster) can read and write to both R1 and R2 devices with SRDF/Metro ensuring that each copy remains current, consistent, and addressing any write conflicts which may occur between the paired SRDF devices23. References: Dell EMC PowerMax and VMAX All Flash: SRDF/Metro Overview and Best Practices, Deploying Dell EMC SRDF/Metro Smart DR with Microsoft SQL Server for Physical and Virtual Environments

An SRDF/Metro device pair was in an ActiveActive state, meaning that both the R1 and R2 devices were read/write accessible to the host or hosts. A link failure between arrays occurs, causing the device pair to become Not Ready (NR) on the SRDF link. SRDF/Metro responds by making the non-biased or R2 paired device inaccessible (not ready) to the host or host cluster, while keeping the biased or R1 paired device accessible (ready). This ensures that there is no data inconsistency or split-brain scenario between the two sites. The device pair enters an Active Bias state, which indicates that only one side of the pair is active and has a bias attribute set. The bias attribute determines which side of the pair remains accessible in case of a link failure. By default, the bias is set to the R1 side of the pair, but it can be changed using the symrdf set bias command. The application continues running on the R1 side, and the link failure is addressed. Once the link is restored, the device pair resumes the ActiveActive state and both devices become accessible again.

References:

• SRDF/Metro overview
• VMware vSphere Metro Storage Cluster (vMSC) with Dell PowerMax and Dell EMC VMAX SRDF/Metro
• Understanding bias

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. A Service Level is a predefined set of performance attributes that can be applied to a storage group to ensure consistent and predictable performance. A Service Level specifies a target response time, an upper response time limit, and a lower response time limit for the storage group. If the application owner wants to improve theperformance of their application, they can adjust the Service Level to a higher level of service, which will provide lower response times and higher priority for the storage group. Unisphere for PowerMax provides five predefined Service Levels: Diamond, Platinum, Gold, Silver, and Bronze, as well as an Optimized option that automatically adjusts the Service Level based on workload characteristics. The application owner can choose a higher Service Level from these options or create a custom Service Level with their own performance parameters.

References:

• Dell EMC PowerMax: Service Levels for PowerMaxOS
• Dell Unisphere for PowerMax 10.0.0 Product Guide

Unisphere for PowerMax and Solutions Enabler have different ways of managing user permissions. Unisphere has a more explicit authentication mechanism for users, where each user must have a username and password to log in to the Unisphere interface. Unisphere also supports role-based access control (RBAC), where each user can be assigned one or more roles that define their level of access to the storage system resources and operations. Unisphere maintains the user and role information in a symauth database, which can be shared with Solutions Enabler. Solutions Enabler, on the other hand, uses the operating system user credentials to authenticate users. Solutions Enabler does not require users to have a username and password to run commands, but it checks the symauth database to verify if the user has the appropriate role to perform the requested operation. Solutions Enabler also supports RBAC, where each user can be assigned up to four roles that define their level of access to the storage system resources and operations.

References:

• Unisphere for PowerMax User Management
• Solutions Enabler User Management

The correct answer is D. When an SRDF/A MSC trip event occurs, the Receive Delta Set on the target arrays is checked for completeness. If the Receive Delta Set is incomplete on any of the target arrays, the session is marked as Cleanup required. This means that the data on the target arrays is not consistent and needs to be cleaned up before resuming SRDF/A replication. The symstar cleanup command can be used to discard the incomplete Receive Delta Set data and resume SRDF/A replication from the last consistent point1