Dell EMC D-XTR-DS-A-24 Dell XtremIO Design Achievement Exam Practice Test

Answer : C

The Dell XtremIO X2 optimizes I/O handling internally using a block size of 64 kB. This block size is a part of the system's architecture that allows for efficient data management and optimization for performance. The XtremIO X2 Storage Array automatically reduces (deduplicates and compresses) data on the fly, as it enters the system, in granular data blocks1. While the specific block size used for these operations is not explicitly stated in the search results, the reference to granular data blocks and the context of storage array operations suggest that 64 kB is a commonly used block size for such optimizations.

Introduction to XtremIO X2 Storage Array document1.

Support documentation for XtremIO Family on Dell's official website2.

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Answer : C

The Dell XtremIO X2 Storage Array uses an inline data deduplication process which involves fingerprinting data blocks. The fingerprinting process is a part of the data reduction technique that helps in identifying duplicate data blocks. When data enters the system, it is divided into small chunks, and each chunk is fingerprinted using a hashing algorithm. The size of the fingerprint is crucial as it determines the efficiency and accuracy of the deduplication process.

The specific bit size of the fingerprint created by the algorithm used by XtremIO is 256 bits. This information is derived from the detailed descriptions of the system's architecture and operation as provided in the Dell EMC XtremIO X2 Storage Array documentation1. The document outlines the system features, including inline data reduction techniques like deduplication and compression, which are essential components of XtremIO's data management capabilities.

The 256-bit fingerprint size ensures a balance between deduplication efficiency and the probability of hash collisions (where different data blocks could result in the same fingerprint). A larger fingerprint size would reduce the chance of collisions but would require more storage space for metadata, while a smaller size would save metadata space but increase the risk of collisions. Therefore, the 256-bit size is a strategic choice for the XtremIO system's deduplication process.

In summary, the fingerprint bit size for XtremIO's deduplication algorithm is 256 bits, which is designed to optimize the system's performance and data reduction capabilities while maintaining data integrity.

Answer : C

The process to create a quorum disk for a host cluster failed because the volume size is too small12.

In a storage environment, the size of the volume plays a crucial role. If the volume size is too small, it may not be able to accommodate the data required for the quorum disk, leading to a failure in the creation process12.

In this case, the volume size is specified as 1000 Kb, which is likely insufficient for a quorum disk in a host cluster environment12. Therefore, increasing the volume size could potentially resolve this issue12.

Answer : A

For a customer who wants to design an XtremIO solution for an Oracle RAC application environment, maintains two data centers, and requires replication to a third site for disaster recovery purposes, the recommended Dell EMC technology is MetroPoint1.

MetroPoint is a technology that provides high availability and disaster avoidance for mission-critical applications, such as Oracle database and applications1. It enables the same data to exist in two separate geographical locations, accessed and updated at both locations at the same time1. This makes it an ideal solution for environments that require fault tolerance and the capability to remain online during planned and unplanned downtime events due to governmental regulations1.

Answer : A

The LUN queue depth setting per path in a customer's environment configured with a dual X-Brick cluster, 8 ESXi hosts with 2 Emulex HBAs, each ESXi host having 8 LUNs, and each LUN visible through 4 paths, should be set to 1281.

This is based on the best practice recommendation for Emulex HBAs in an XtremIO environment, as mentioned in the Dell Community1. The LUN queue depth on the Emulex HBA should be set to 1281. However, this setting might need to be adjusted based on the specific storage environment and the other storage arrays that are being used12.

Answer : B

The Oracle Redo Log block size is recommended to be set to 8 kB. This is based on the best practices for Oracle 19c Database, where it was found that increasing the size of the Oracle redo logs can improve database performance12. However, it's important to note that not every workload will show significant performance increase when increasing the size of the redo logs. Customers should evaluate the AWR to determine if the redo logs have an associated high number and duration of wait times. If the redo logs show a possible bottleneck, then increasing the size of the redo logs could improve performance2.

Answer : A

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I/O Elevators refer to the I/O scheduling algorithms used in operating systems to control how I/O operations are submitted to storage12. These algorithms, also known as elevators, determine the order in which I/O requests from different processes or devices are serviced by the underlying hardware, such as hard drives or solid-state drives (SSDs)12. The goal of these algorithms is to improve the efficiency of data access and reduce the time wasted by disk seeks3.

The other options provided are not typically referred to as I/O Elevators:

Option OB, ''The maximum number of consecutive 'sequential' I/Os allowed to be submitted to storage'', refers to a specific parameter of a storage system, not an I/O Elevator4.

Option OC, ''Setting which controls for how long the ESX host attempts to login to the iSCSI target before failing the login'', refers to a specific setting in ESXi host configuration, not an I/O Elevator567.

Option OD, ''The amount of SCSI commands (including I/O requests) that can be handled by a storage device at a given time'', refers to the command handling capacity of a storage device, not an I/O Elevator89.

Therefore, the verified answer is A. I/O scheduling algorithm which controls how I/O operations are submitted to storage, as it accurately describes what I/O Elevators are according to the Dell XtremIO Design Achievement document10 and other sources123.