Correct Answer: B

The volume size must be specified in MB, GB, TB, and not in KB.

Incorrect Answers:

D: Quorum disks on XtremIO The SAN Volume Controller cluster will select disks that are presented by the XtremIO storage system as quorum disks. To maintain availability for the cluster, ideally each quorum disk should reside on a separate disk subsystem.

The quorum device can be any disk device that is shared between two or more nodes. EMC Symmetrix, VNX series, or XtremIO devices are commonly used for this purpose.

References: https://vcdx133.com/2014/09/14/emc-xtremio-provisioning-a-lun/

Correct Answer: B

resxtop is a command to retrieve performance statistics. This command is included in vSphere command line interface (CLI) and is part of the vSphere Management Assistant (vMA), which is an equivalent to esxtop that runs only inside an ESX service console.

Incorrect Answers:

A: esxtop runs only inside an ESX service console.

D: Use the iostat command to report statistics about disk input and output, and to produce measures of throughput, utilization, queue lengths, transaction rates, and service time.

References: www.emc.com/collateral/TechnicalDocument/docu5265.pdf, page 22

Correct Answer: A

Noting the inefficiencies in VMware's NMP driver, EMC developed a set of drivers specifically designed to overcome these limitations and improve the performance and reliability of the data passing between an array and a server. EMC developed the PowerPath family of products optimized specifically for Linux, Microsoft Windows, and UNIX Operating Systems as well as PowerPath/VE for VMware vSphere and Microsoft Hyper-V hypervisors.

PowerPath is installed on hosts to provide path failover, load balancing and performance optimization VPLEX engines (or directly to the XtremIO array if VPLEX is not used).

Note: VMware, with the cooperation of its storage partners, developed a Native Multipathing Plug-in (NMP). VMware NMP was designed to distribute the load over all the available paths and provide failover protection in the case of path, port or HBA failure, but it has not been fully optimized to work with the controllers in a storage systems. VMware's NMP Round Robin policy does not have the intelligence that PowerPath has as PowerPath uses testing and diagnostics to continually monitor an environment to determine the optimal path for queuing requests and will adapt to current conditions.

References: https://www.emc.com/collateral/analyst-reports/emc-taneja-group-powerpath-tb.pdf

Correct Answer: D

Configuring vSphere Native Multipathing.

For best performance, it is recommended to do the following:

Set the native round robin path selection policy on XtremIO volumes presented to the ESX host.

References: https://itzikr.wordpress.com/2015/12/16/host-configuration-for-vmware-vsphere-on-emcxtremio/

Correct Answer: D

Architecting a database on an All Flash Array (AFA) like EMC's XtremIO is best done by reviewing practices to optimize I/O performance. One consideration is the use of Advanced Format and how it impacts the performance of the database Redo logs. Advanced Format refers to a new physical sector size of 4096 bytes (4KB) replacing original 512 byte standard.

References: https://community.emc.com/community/connect/everything_oracle/blog/2014/07/18/xtremiobest-practices-advanced-format-512e-and-native-modes

Correct Answer: C

Per IDC's best practices the toolkit fills the array 2x.

References: https://community.emc.com/docs/DOC-35014

Correct Answer: B

Correct Answer: D

Any copy in the hierarchy tree can be deleted without effecting the parents or children.

Incorrect Answers: B: Deleting a snapshot in the middle of the tree triggers an asynchronous process. This process merges the metadata of the deleted entity's children with that of their grandparents. This ensures that the tree structure is not fragmented.

C: It is possible to create copies of the production volumes in order to protect against logical data corruption. Multiple copies can be created over a short interval in order to provide a fine RecoverPoint Objective (RPO) in a cyclic manner (a superior RPO to a backup).

References: https://www.emc.com/collateral/white-paper/h13035-wp-introduction-to-xtremiosnapshots.pdf, page 14

Correct Answer: C

The system operation is controlled via a stand-alone dedicated Linux-based server, called the XtremIO Management Server (XMS). A single XMS can manage multiple clusters. Multiple cluster management is supported from version 4.0 and up. System version 4.0 supports up to eight clusters managed by an XMS in a given site.

References: Introduction to the EMC XtremIO STORAGE ARRAY (April 2015), page 48

Correct Answer: A

Disk service time T(s) = 32 ms (service time for one I/O).

Response time T(r) is calculated as: T(s) / (1 – Utilization), which here calculates to 32 ms/ (1-0.75) = 128

ms.

References: https://community.emc.com/thread/145100?tstart=0