C90-06A 全真模擬試験 DEMO

問題4: Cloud Storage Device A contains LUN A and can be accessed by external cloud consumers via a
proprietary user portal that is used primarily by cloud consumers to upload and manage data for
backup purposes. Pay-Per-Use Monitor A tracks the amount of data being uploaded and forwards
this information to a billing management system. Cloud Storage Device B is a secondary cloud
storage device. Data from Cloud Storage Device A is replicated synchronously to Cloud Storage
Device B using a storage replication program (not shown). Cloud Storage Device A is further
administered by a cloud resource administrator that works for the cloud provider, who accesses the
cloud storage device via an internal usage and administration portal.
Three different cloud consumers (Sarah. William, Matilda) access Cloud Storage Device A to upload
data for backup purposes (1). These three cloud consumers belong to different
departments within the same organization, and therefore all three share LUN A.
Pay-Per-Use Monitor A collects the storage space data and forwards it to the billing management
system (2).
The cloud provider offers premium and discount storage plans. With the premium plan, the data
stored on Cloud Storage Device A is also replicated to Cloud Storage Device B.
With the discount plan, the data stored on Cloud Storage Device A is not replicated. Both plans are
based on fixed-disk storage allocation. The cost of the premium plan is $5 per week for every GB of
storage space and the cost of the discount plan is $2 per week for every GB of storage space. The
SLA from the cloud provider guarantees availability of 97% for access to Cloud Storage Device A.
The three cloud consumers use Cloud Storage Device A as follows:
-Sara signs up for the discount backup plan and is allocated 50 GBs of storage space. A week later,
she uploads 10 GBs of backup data. A week after that, she uploads another 35 GBs. She later finds
out that for those two weeks her organization was billed $200, which is more than she was
expecting. After she complains to the cloud provider, she learns about how fixed-disk storage
allocation is billed. She asks the cloud provider to change her account to a different
storage plan where she is only billed for the actual amount of storage space she uses at any
given time. The cloud provider assures her that a new system will be set up to accommodate
this request.
-William is on the premium backup plan. He uploads 1 to 3 GBs of important business data every
day. After two weeks of daily uploads, he realizes that the centralized nature of the backup data on
the cloud makes it more convenient for reporting purposes than the distributed nature of the same
data in his on-premise environment. He uses an analysis tool to run queries against the cloud-based
data. However, due to the large quantity of redundant data, the queries end up being ineffective
and take too long to run. He asks the cloud provider to find a solution that can streamline the
cloud-based data by reducing redundancy. By reducing the overall quantity of the data, the analysis
queries will run faster.
-Matilda is on the discount backup plan and uploads backup data on a daily basis. Over the course
of two weeks she uploads over 200 GBs of data. She performs a daily backup at the end of each day
by identifying the data to back up and then using the proprietary user portal to run the cloud
backup procedure. This procedure can take 5 to 45 minutes, depending on the amount of data she
is uploading. Matilda performs this as her last task of the day and therefore initiates the procedure
before she leaves, but does not wait for it to complete. One day, she receives an e-mail from the
cloud provider explaining that the backup procedure from the previous day had failed due to an
unexpected hardware failure that occurred on Cloud Storage Device A.
The notification e-mail goes on to state that this type of failure falls within the 97% availability
guarantee of her organization's SLA, and is therefore in compliance with the current provisioning
agreement. Had a disaster occurred that night, the on-premise data could have been lost and
Matilda would be held accountable. Matilda contacts the cloud provider to demand that the
provisioning agreement be amended to upgrade their existing SLA to the maximum possible
availability (which, for this cloud provider, is 99.999%). The cloud provider agrees to establish a
system to accommodate this request.
Which of the following statements lists the patterns that can be applied to address the three issues
raised by the three cloud consumers?
A. Storage Workload Management, Elastic Disk Provisioning, Centralized Remote Administration
B. Elastic Disk Provisioning, Dynamic Data Normalization, Zero Downtime
C. Storage Maintenance Window, Dynamic Failure Detection and Recovery, Broad Access
D. None of the above.
正解: B