EMC Technology Architect E20-880 Questions & Answers

• Question 81:

  A customer created a Thin LUN, enabled compression on a Pool, and installed their email application environment. The application is showing poor performance. Which workload characteristic of the application would produce poor access times on a compressed LUN?

  A. Small random writes

  B. Small random reads

  C. Sequential reads

  D. Uncompressed or host based data

  Correct Answer: A

• Question 82:

  In VNX with MCx, if the Block compression rate is set to high, what is the initial compression bandwidth?

  A. 25 MB/s

  B. 7 MB/s

  C. 4 MB/s

  D. 32 MB/s

  Correct Answer: A

• Question 83:

  You received a call from a customer asking to help troubleshoot why AVM cannot select dVols from their remaining classic LUNS to create a stripe volume. What could be a reason for this?

  A. LUNs must have the same RAID configuration

  B. LUNs must come from the same RAID groups

  C. LUNs must not exceed 18 TB in size

  D. LUNs must have different RAID configuration

  Correct Answer: A

• Question 84:

  You received a call from a customer asking to help troubleshoot why AVM cannot select dvols from their remaining classic LUNS to create a stripe volume. What could be a reason for this?

  A. LUNs must come from different RAID groups

  B. LUNs must have different RAID configuration

  C. LUNs must not exceed 18 TB in size

  D. LUNs must come from the same RAID group

  Correct Answer: A

• Question 85:

  You are migrating a database on NFS to a new VNX. The customer notes that you have designated only SAS drives for the database transaction logs and not any Flash drives. The customer believes that the Flash drives will greatly increase transaction log performance.

  What is the reason that you chose SAS drives?

  A. Flash drives are most efficient for small block random I/O

  B. SAS drives are just as efficient for sequential I/O

  C. The transaction logs vary in size and can be sequential or random I/O

  D. Databases cannot sustain multiple concurrent I/Os.

  Correct Answer: B

• Question 86:

  You have a VNX customer who is concerned that you created multiple LUNs within the same Flash drive RAID group and believes this will create disk contention with reduced performance.

  What is the reason to create the Flash drive LUNs in this manner?

  A. Flash drives have multiple internal channels which can service concurrent I/O's

  B. The Flash drive RAID group was carved for both FAST Cache and Flash drive file pool use.

  C. Flash drive RAID group drives used for file must be created as small size LUNs and concatenated

  D. Flash drives have significantly quicker response times and therefore disk contention is not an issue

  Correct Answer: A

• Question 87:

  Your customer has an application on VNX File storage. The customer allocated the storage using Manual Volume Management in order to achieve the best performance. The customer noted that the file system used up all of the storage from the File LUNs even though the size of the file system is much less than the total of the File LUNs used.

  Why was all of the storage used when the file system was created?

  A. The customer did not change the default_slice_flag to "yes" when creating the file pool

  B. The file pool is_dynamic flag is set to "yes" and has taken up all of the LUN space

  C. Additional LUNs have been used to create the file system because is_greedy is set to "yes"

  D. The stripe_size flag was set to "yes" but no value was entered when the file system was created

  Correct Answer: A

• Question 88:

  A customer implemented your VNX for File design for a high-performance CAD/CAM application. The design specified several NFS clients, each accessing a single file system in a single-threaded manner. You need to guarantee that each file system resides on an exclusive LUN set.

  Which value would you change?

  A. default_slice_flag

  B. is_greedy

  C. is_dynamic

  D. stripesize

  Correct Answer: A

• Question 89:

  You received a call from a customer asking to help troubleshoot why they cannot select dvols using MVM from their remaining pool LUNS to create a stripe volume.

  What could be a reason for this?

  A. All Thick LUNs must be used first

  B. All Thin LUNs must be used first

  C. LUNs must not exceed 18 TB in size

  D. LUNs must be on the same SP

  Correct Answer: A

• Question 90:

  What is the best practice for configuring VNX OE File SavVol LUNs?

  A. They should use a separate storage pool whenever possible

  B. You should always enable fast cache for SavVol LUNs

  C. Never use NL-SAS for SavVol LUNs for SAS pools

  D. Create SavVol LUNs using manual volume management

  Correct Answer: A