EMC DEE-1111 Dumps

In a Concurrent SRDF/Star configuration failure, the first step to recover is to switch to the 1st Target Site. This is because in a Concurrent SRDF/Star configuration, there are two target sites and one source site. If there’s a failure, the source site can switch to either of the target sites based on the business continuity plan1. References: Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

 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

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

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

 In PowerMax, each RAID group is divided into 64 logical blocks known as TDATs (Thin Device Addressable Tracks). Each TDAT is configured to hold data at a given data reduction level, from 1:1 uncompressed data all the way to 16:11. References: Data Protection Schemes | Dell PowerMax: Reliability, Availability, and Serviceability | Dell Technologies Info Hub

The correct sequence of steps to configure and bring up an SRDF/Star environment is as follows:

• Verify SRDF/Star control host connectivity and array settings. This step involves checking the network connectivity between the control host and the three arrays involved in the SRDF/Star configuration, as well as verifying the array settings such as RDF mode, RDF consistency, and RDF emulation. The control host is the host that runs the Solutions Enabler SYMCLI commands to manage the SRDF/Star configuration.The three arrays are the primary array, the secondary array, and the tertiary array.1
• Enable SRDF/Star configuration. This step involves enabling the SRDF/Star feature on the primary array using the symstar enable command. This command also creates a STAR control device group on the primary array, which contains a single device that acts as a control point for the SRDF/Star configuration.The STAR control device group must have a unique name and number across all arrays.1
• Add BCV devices to the SRDF/Star configuration. This step involves adding Business Continuance Volume (BCV) devices to the STAR control device group on the primary array using the symstar add bcv command. BCV devices are local copies of data that can be used for backup, restore, or testing purposes. BCV devices are required for SRDF/Star configurations to enable fast recovery in case of a disaster.The number of BCV devices must match the number of R1 devices in the SRDF/Star configuration.1
• Create an SRDF/Star composite group and options file. This step involves creating an SRDF/Star composite group on the control host using the symstar create command. An SRDF/Star composite group is a logical grouping of devices that span across three arrays and have different SRDF roles: R11, R21, and R22. An R11 device is an R1 device that is paired with another R1 device in a different SRDF group. An R21 device is an R2 device that is paired with another R1 device in a different SRDF group. An R22 device is an R2 device that is paired with another R2 device in a different SRDF group.The symstar create command also creates an options file that contains various parameters for the SRDF/Star configuration, such as RDF mode, RDF consistency, RDF emulation, and bias setting.1
• Perform the symstar setup operation and create composite groups on target sites. This step involves performing the symstar setup operation on the control host using the symstar setup command. This command establishes the SRDF/Star configuration by creating RDF pairs between devices in different arrays, creating RDF groups on each array, creating composite groups on each array, and synchronizing data across all devices.The symstar setup command also creates composite groups on the secondary and tertiary arrays using the same name and number as the composite group on the primary array.1

References:

• Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

The two factors that define Capacity Management are I/O capacity and storage capacity. I/O capacity refers to the ability of the system to handle the incoming and outgoing data traffic from the hosts or applications. Storage capacity refers to the amount of disk space available to store the data. Capacity Management is the process of planning, monitoring, and optimizing the use of these resources to ensure optimal performance, availability, and efficiency of the system.

References:

• Dell EMC PowerMax: Family Overview
• System Resource Usage

The alert settings required are a first level warning at 10 ms and a second level critical alert at 15 ms. These settings will ensure that high I/O response times for a specific storage group are tracked and appropriate actions are taken when the response times exceed the specified thresholds. References: Dell EMC PowerMax: Service Levels for PowerMaxOS

The correct sequence of actions that take place on a Write Miss is as follows:

• Host sends requests to FE director and no cache slots are found.This happens when the cache is full or the desired cache slot is locked by another request1.
• FE finds available slot by polling.This involves the FE director scanning the cache for an available slot or waiting for a slot to be freed by the BE director2.
• FE sends data from host to mirrored cache locations.This involves the FE director writing the data from the host to two mirrored locations in the cache, one on each engine2.
• FE responds to host to acknowledge successful write.This involves the FE director sending a signal to the host that the write operation is completed, even though the data is not yet written to disk2.
• BE destages data as a high-priority task to make slots available.This involves the BE director flushing some of the existing write pending data from the cache to the disk, in order to free up some cache slots for new write requests2.
• BE destages new data to disk at a later time.This involves the BE director writing the new data from the cache to the disk, according to the destaging algorithm and priority2.

The data characteristics represent an Online Transaction Processing (OLTP) workload profile. OLTP workloads typically consist of a high percentage of small, random I/O operations2. In this case, 80% of the I/O is generated with 8 KB random small blocks, which is characteristic of OLTP workloads2. References: Use DISKSPD to test workload storage performance - Azure Stack HCI | Microsoft Learn

 The symrdf split command is used to suspend SRDF/A replication and make both R1 and R2 devices read/write enabled. This is useful for testing purposes or for creating point-in-time copies of data on both sides. The symrdf establish command can be used to resume SRDF/A replication after a split operation. The exhibit shows that both R1 and R2 devices are read/write enabled and have a Split status, which indicates that a symrdf split command was issued next2

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 symauth command is used to manage user authorization for SYMCLI commands. The exhibit shows the output of the symauth -list command, which displays the user groups and access types defined for SYMCLI commands. The output shows that there are two user groups: AdminGrp and EmcMgmtGrp. The AdminGrp group has ADMINRD access type, which means that users in this group can run any SYMCLI command with read-only access. The EmcMgmtGrp group has BASECONTROL access type, which means that users in this group can run only a subset of SYMCLI commands with read/write access. Therefore, the correct description of a possible configuration created by SYMACL is hosts that are part of AdminGrp group2

The symstar halt command is used to write disable devices and synchronize SRDF data to remote sites in an SRDF/Star configuration. This command ensures that all sites have a consistent copy of data before switching the workload site from one site to another. Therefore, the symstar halt command should be used before the workload switch in case of a disaster at the workload site of an SRDF/Star configuration1

the maximum number of SCM RAID groups that can be added to a two-engine PowerMax 2000 would depend on various factors including the specific configuration of the system and the capacity requirements.