EMC DCS-IE DES-1423 Questions & Answers

• Question 61:

  In Isilon OneFS, what is a characteristic of CoW with snapshots?

  A. Used for small changes, inodes, and directories.

  B. Avoids the double write penalty.

  C. Increases file fragmentation.

  D. Used for more substantial changes such as deletes.

  Correct Answer: A

  With copy on write, as the name suggests, a new write to HEAD results in the old blocks being copied out to the snapshot version first. Although this incurs a double write penalty, it results in less fragmentation of the HEAD file, which is better

  for cache prefetch, etc.

  Typically, CoW is most prevalent in OneFS and is primarily used for small changes, inodes and directories.

  Reference: https://www.dellemc.com/resources/en-us/asset/white-papers/products/storage/h15048-wp-next-gen-data-protection-snapshot-iq.pdf

• Question 62:

  What defines FEC link aggregation mode?

  A. Switches to the next interface when the primary interface becomes unavailable.

  B. Balances outgoing traffic based on hashed protocol header information that includes source and destination addresses, and VLAN tag.

  C. Balances outgoing traffic based on hashed protocol header information that includes source and destination addresses.

  D. Balances outbound traffic across all active ports in the aggregated link.

  Correct Answer: B

  Reference: http://doc.isilon.com/onefs/8.0.0/help/en-us/ifs_r_link_aggregation_methods.html

• Question 63:

  What impact can obsolete drive firmware have on an Isilon cluster?

  A. Reduces administrative overhead and increases performance.

  B. Affects redundancy settings and FEC coding.

  C. Affects cluster performance or hardware reliability.

  D. Increases runtime and cluster performance.

  Correct Answer: C

  Reference: http://doc.isilon.com/onefs/7.2.0/help/en-us/GUID-398C2422-1CA5-4AE0-8F3D-09F589C82E6E.html

• Question 64:

  When reviewing the actual protection output of N+4/2, what does the number "4" represent?

  A. FEC stripe units per stripe

  B. Hard drives used per stripe

  C. Volume stripes per file system

  D. FEC stripe units per file system

  Correct Answer: A

  It's OneFS FEC protection nomenclature for our "hybrid" protection polices. More generally, it's written as:

  N+M/b

  where "N" is the number of data stripe units in a stripe, "M" is the number of FEC stripe units in a stripe, and "b" is the number of stripe units in a stripe which are allowed to reside on the same node.

  Reference: https://www.dell.com/community/Isilon/Isi-get-output/td-p/7085467

• Question 65:

  DRAG DROP Refer to the Exhibit.

  

  In an Isilon environment, match the connectivity type to the proper numerical port reference shown in the exhibit.

  Select and Place:

  

  Correct Answer:

  

• Question 66:

  DRAG DROP

  What is the correct sequence of actions performed by OneFS to generate an access token?

  Select and Place:

  

  Correct Answer:

  

• Question 67:

  DRAG DROP

  What is the correct sequence of steps in a client read operation?

  Select and Place:

  

  Correct Answer:

  

• Question 68:

  DRAG DROP

  What is the correct hierarchy of the Job elements structure?

  Select and Place:

  

  Correct Answer:

  

  Reference: https://www.dellemc.com/resources/en-us/asset/white-papers/products/storage/h12570-wp-isilon-onefs-job-engine.pdf (6)