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 : 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 : A

When troubleshooting SAN performance problems, a key indicator of a physical issue is a high CRC (Cyclic Redundancy Check) error count. CRC errors are indicative of corrupt data packets during transmission, which often points to issues such as faulty cables, bad ports, or other physical problems in the network infrastructure. High CRC error counts can lead to retransmissions, reduced throughput, and overall degradation of SAN performance. Addressing the physical components associated with high CRC error counts is essential for restoring optimal SAN operations.

While the specific Dell XtremIO Design document was not available, general SAN troubleshooting guidelines and best practices indicate that CRC errors are a critical metric to monitor for physical connectivity issues1.

Additional resources on SAN performance troubleshooting can be found in the support documentation for the XtremIO Family on Dell's official website2.

=========================

Answer : B

In a Dell XtremIO X2-R system, a four X-Brick cluster configuration includes two InfiniBand Switches1. Each InfiniBand Switch in a multi X-Brick system, such as the X2-R, is included to interconnect the X-Bricks within the cluster. While the specific number of ports is not directly stated in the search results, the configuration implies a high number of ports to support the connectivity between multiple X-Bricks. Based on the available information and typical configurations of such systems, it is reasonable to infer that each InfiniBand Switch would have 36 ports to provide the necessary interconnectivity for a four X-Brick cluster.

The XtremIO X2 Specifications document provides details on system configurations and components, including InfiniBand Switches1.

Additional information on InfiniBand Switches and their role in multi X-Brick systems can be found in the XtremIO X2 Specification Sheet2.

Answer : A

To accommodate a workload that generates 500,000 IOPS with a maximum bandwidth of 14 GB/s, the recommended XtremIO X2 solution would be 4 X-Bricks. This recommendation is based on the specifications that a fully populated X-Brick module with 72 flash drives supports 220,000 IOPS1. Therefore, to support 500,000 IOPS, more than two X-Bricks are required. Additionally, the bandwidth requirement of 14 GB/s must be considered, and typically, more X-Bricks can provide higher bandwidth capabilities.

Dell EMC Ready Solutions for Oracle with XtremIO X2 document2.

Reference Architecture Guide---Ready Solutions for Microsoft SQL: Design for Dell EMC XtremIO1.

=========================

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.

Answer : D

When designing an Oracle solution for a customer using XtremIO, it's important to consider the best practices for performance and efficiency.

Option OD, ''Allocate multiple LUNs per host, Use Thin formatting on the ESXi'', is a recommended best practice for Oracle environments12.

Allocating multiple LUNs per host can help distribute the I/O load more evenly across the storage system, which can improve performance1. This is particularly important in Oracle environments, where there can be a high level of concurrent I/O activity1.

Using Thin formatting on the ESXi is also recommended. Thin provisioning is a storage provisioning method that optimizes the efficient use of available space. For a thin virtual disk, ESXi provisions the entire space required for the disk's current and future activities, but the thin disk uses only as much storage space as the disk needs for its initial operations3. If the disk requires more space, it can expand into its entire provisioned space3.

The other options, while they may be part of the overall