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

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 : 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 : A

The Dell EMC XtremIO X2 storage array offers flexible scaling options with building blocks called X-Bricks1. The system can start with a single X-Brick and scale up to 72 SSDs for a single X-Brick1. When additional performance and capacity are required, the system can be expanded by adding additional X-Bricks1.

Among the options provided, VMware is the host OS that supports both 512 bytes and 4 KB XtremIO logical block (LB) volumes23. VMware vSphere 6.7 and later versions support both 512-byte and 4K logical block sizes23. This is because VMware ESXi detects and registers the 4Kn devices and automatically emulates them as 512e3.

The other options, while they may be part of the overall process, are not specifically known to support both 512 bytes and 4 KB XtremIO logical block (LB) volumes:

Linux typically supports multiple file system block sizes of 512, 1024, 2048, and 40964. However, it's not specifically mentioned that it supports both 512 bytes and 4 KB XtremIO logical block volumes5.

IBM AIX also supports multiple file system block sizes of 512, 1024, 2048, and 40966. But again, it's not specifically mentioned that it supports both 512 bytes and 4 KB XtremIO logical block volumes7.

HP-UX does not specifically mention support for both 512 bytes and 4 KB XtremIO logical block volumes89.

Therefore, the verified answer is A. VMware, as it is the host OS that supports both 512 bytes and 4 KB XtremIO logical block (LB) volumes23.

Answer : D

The Fill phase in the PoC Toolkit should involve scattering writes across the entire storage system to simulate ordinary use and to ensure that the array is adequately prepared for the real-world workload.

Answer : C

XtremIO XVC (XtremIO Virtual Copies) allows for efficient snapshot management and operations, including the refresh of volumes. One of the key features of XVC is that it enables the refresh of a production volume from a snapshot without requiring the volume to be unmounted from the host. This capability is designed to minimize disruption and maintain continuous availability of data to applications during refresh operations. The refresh operation is handled within the XtremIO storage array, and the production volume remains accessible to the host during this process1.

The Dell XtremIO Design Achievement document provides information on the capabilities and features of XtremIO X2 systems, including XVC operations1.

Additional details on XVC refresh operations can be found in the support documentation for the XtremIO Family on Dell's official website2.

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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.

Answer : B

When designing a Virtual Desktop Infrastructure (VDI) solution, it's important to consider the best practices for performance and efficiency.

Option OB, ''Align data on 4 kB boundariesAllocate multiple XtremIO LUNs to each host'', is a recommended best practice for VDI environments12. This is because aligning data on 4 kB boundaries can help to optimize the performance of the storage system12. The XtremIO storage array uses a 4 kB data block size, so aligning data on 4 kB boundaries can help to ensure that data is efficiently stored and retrieved12.

Allocating multiple XtremIO LUNs to each host can also help to distribute the I/O load more evenly across the storage system, which can improve performance12. This is particularly important in VDI environments, where there can be a high level of concurrent I/O activity12.

The other options, while they may be part of the overall process, are not specifically recommended for VDI environments:

Option OA, ''Align data on 8 kB boundariesPut all VDI-related data on one large LUN'', is not recommended because aligning data on 8 kB boundaries does not match the 4 kB data block size used by the XtremIO storage array12. Also, putting all VDI-related data on one large LUN can lead to performance issues due to the high level of concurrent I/O activity in VDI environments12.

Option OC, ''Align data on 4 kB boundariesPut persona and user data on XtremIO LUNs'', is not recommended because persona and user data typically do not require the high performance provided by XtremIO LUNs12.

Option OD, ''Align data on 8 kB boundariesPut the master VM image on an XtremIO LUN'', is not recommended because aligning data on 8 kB boundaries does not match the 4 kB data block size used by the XtremIO storage array12.

Therefore, the verified answer is B. Align data on 4 kB boundariesAllocate multiple XtremIO LUNs to each host, as it provides the most suitable solution for VDI environments according to the Dell XtremIO Design Achievement document12.