EMC E20-526 Online Practice Questions and Exam Preparation

EMC E20-526 Online Questions & Answers

• Question 61:

  A customer has purchased a two X-Brick XtremIO array with a physical XtremIO Management Server (XMS). The customer plans to use all Fibre Channel connectivity in the environment.

  What are the physical connectivity requirements for the cluster?

  A. 1 Copper Ethernet connection, 4 Fibre Channel Optical connections
  B. 3 Copper Ethernet connections, 8 Fibre Channel Optical connections
  C. 4 Copper Ethernet connections, 16 Fibre Channel Optical connections
  D. 5 Copper Ethernet connections, 8 Fibre Channel Optical connections
  B. 3 Copper Ethernet connections, 8 Fibre Channel Optical connections

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  EMC XTREMIO 4.0 SYSTEM SPECIFICATIONS

  

  References: http://www.aecl.com/AECWeb/media/Assets/PDF/h12451-xtremio-4-system-specifications-ss.pdf

• Question 62:

  A customer wants to purchase an XtremIO array. After the array is installed, the customer wants to initially disable encryption. What is the result of enabling encryption on an array that is already being used?

  A. Data will remain in place but the XtremIO cluster services will need to be temporarily shutdown.
  B. Data will remain in place and there will be no interruption to the XtremIO cluster services.
  C. Data will be erased but there will be no interruption to the XtremIO cluster services.
  D. Data will be erased and the XtremIO cluster services will be temporarily shutdown.
  A. Data will remain in place but the XtremIO cluster services will need to be temporarily shutdown.

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  Disable Encryption and Non-Encrypted Models

  This version [Ver. 4.0.2-65] allows disabling the Data at Rest Encryption (DARE), if desired. Disabling and Enabling is done when the cluster is stopped.

  References: https://samshouseblog.com/2015/12/29/new-features-and-changes-in-xtremio-ver-4-0-2-65/

• Question 63:

  A customer wants to use the Cinder driver to manage XtremIO storage in an OpenStack environment. What is a potential concern?

  A. Compression is not supported
  B. Deduplication is not supported
  C. Snapshots of snapshots are not supported
  D. Volume expansion cannot be reversed
  D. Volume expansion cannot be reversed

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  Incorrect Answers:

  B: OpenStack Cinder features include:

  Clone a volume: With inline deduplication, compression and thin provisioning.

  C, D: EMC XtremIO OpenStack Block Storage driver, supported operations: Create, delete, clone, attach, and detach volumes Create and delete volume snapshots Create a volume from a snapshot Copy an image to a volume Copy a volume to an image Extend a volume

  References: https://docs.openstack.org/juno/config-reference/content/XtremIO-cinder-driver.html https://www.emc.com/collateral/data-sheet/h13287-ds-xtremio-openstack.pdf

• Question 64:

  

  Refer to the exhibit.

  A customer has a VMware Horizon View environment with the following characteristics: One X-Brick XtremIO cluster 100% read during a boot storm 8K read/writes

  What is the maximum recommended number of VDIs the XtremIO cluster can support during a boot storm?

  A. 1625
  B. 1833
  C. 3250
  D. 5094
  A. 1625

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  EMC estimates that 150 IOPS per desktop is required in a boot storm. As per table the recommended number of VDIs then is 243,831/ 150, which equals 1625. References: https://www.emc.com/collateral/white-papers/h14279-wp-vmware-horizon-xtremio-design-considerations.pdf, page 32

• Question 65:

  You have been asked to design an XtremIO storage array solution that will be used for two large applications workloads. One overload will generate approximately 150,000 write IOPs with an average 4 kB I/O size. The second write workload will have an average I/O size of 128 kB and will generate approximately 2 GB/s of throughput.

  At a minimum, how many X-Bricks are needed in a single cluster to meet this requirement?

  A. 2
  B. 4
  C. 6
  D. 8
  A. 2

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  Second write workload IOPS = 2 GB/s divided by 128 kB = 2 x 1,073,741,824 / (128 x 1,024) = 16384 IOPs. Total IOPS required would be 150,000, from the first workload, plus 16384, totaling 166384.

  A 2 X-Brick cluster provides 300K Read/write IOPS so it would be adequate.

  Storage capacity and performance scale linearly, such that two X-Bricks supply twice the IOPS, four X-Bricks supply four times the IOPS, six X-Bricks supply six times the IOPS and eight X-Bricks supply eight times the IOPS of the single X-

  Brick configuration.

  Note: Choose an EMC XtremIO system and scale out linearly by adding more XtremIO X-Bricks.

  

  References: https://store.emc.com/en-us/Product-Family/EMC-XtremIO-Products/EMC-XtremIO-All-Flash-Scale-Out-Array/p/EMC-XtremIO-Flash-Scale-Out

• Question 66:

  Which actions are initiated when a snapshot is created on an XtremIO array?

  A. Parent object becomes read only and two auxiliary volumes are created
  B. Parent object remains writeable and one auxiliary volume is created
  C. Parent object remains writeable and two auxiliary volumes are created
  D. Parent object becomes read only and one auxiliary volume is created
  A. Parent object becomes read only and two auxiliary volumes are created

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  When a copy is created, the volume's existing metadata becomes an "ancestor" entity (parent object) that is shared between the production volume and the copy. New empty containers are created for subsequent changes to both the production volume and the virtual copy volume. Therefore, the act of creating a copy is instantaneous and involves no data or metadata copies.

  

  References: https://www.emc.com/collateral/white-paper/h13035-wp-introduction-to-xtremio-snapshots.pdf, pages 18

• Question 67:

  When creating XtremIO volumes for a host, which operating systems will benefit by changing the default logical block size for applications consisting of 4 KB I/Os?

  A. Microsoft Windows and RHEL
  B. VMware ESX and Microsoft Windows
  C. RHEL and IBM AIX
  D. Sun Solaris and HP-UX
  B. VMware ESX and Microsoft Windows

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  With VMware ESX 5.5, the VMware hypervisor cannot work with LUNs that use a logical block size of 4K. When using VMware, be sure to specify Normal (512 LBs) from your XtremIO array. References: https://gruffdba.wordpress.com/2015/08/02/4k-logical-block-size-size-fails-on-vmware/