Cloud storage and sync in Intro to Computing - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

How does cloud storage keep your files safe?

Imagine you save a photo on your phone and it uploads to cloud storage. What is the main way cloud storage keeps your files safe?

A By making multiple copies of your files on different servers in different places

B By deleting old files after 24 hours to save space

C By only allowing you to access files when connected to Wi-Fi

D By compressing files so they take less space but lose quality

💡 Hint

Think about how losing one copy of a file might not lose your data if there are backups.

Cloud storage keeps your files safe by storing multiple copies (backups) in different locations. This way, if one server fails, your files are still safe elsewhere.

❓ trace

intermediate

What happens when you edit a synced file?

Look at this flowchart describing what happens when you edit a file saved in cloud storage synced to your computer:

• Edit file on computer
• File marked as changed
• Sync client uploads changes to cloud
• Cloud updates file version
• Other devices download updated file

What is the correct order of these steps?

A 2,1,3,4,5

B 1,3,2,4,5

C 1,2,3,4,5

D 1,2,4,3,5

💡 Hint

Think about what happens immediately after you edit a file before syncing.

First you edit the file, then the system marks it as changed. The sync client uploads the changes, the cloud updates the file version, and finally other devices download the update.

❓ Comparison

advanced

Which cloud sync method handles conflicts best?

Two people edit the same cloud file at the same time on different devices. Which sync method best prevents data loss?

A Last write wins: the last saved change overwrites earlier ones

B No sync: changes are never uploaded to avoid conflicts

C File locking: only one person can edit at a time, others wait

D Versioning: all changes are saved as separate versions to review

💡 Hint

Think about how you can recover previous versions if mistakes happen.

Versioning saves all changes as separate versions, allowing users to review and restore any version, preventing data loss from conflicts.

❓ identification

advanced

Identify the cloud sync problem from this scenario

Maria edits a document offline and saves it. Meanwhile, John edits the same document online. When Maria reconnects, her changes overwrite John's without warning. What problem happened?

A File corruption due to network error

B Sync conflict without conflict resolution

C File encryption failure

D Version rollback to an older file

💡 Hint

Think about what happens when two people edit the same file separately.

This is a sync conflict where changes from different sources overwrite each other because the system did not detect or resolve the conflict properly.

🚀 Application

expert

Calculate storage usage with sync and versioning

You have a cloud folder synced to your computer. The folder contains 3 files: A (2MB), B (3MB), and C (5MB). You edit file B twice, creating 2 extra versions (each 3MB). How much total cloud storage is used?

A 16 MB

B 11 MB

C 9 MB

D 13 MB

💡 Hint

Add the original files plus all versions stored in the cloud.

The original files total 2 + 3 + 5 = 10 MB. Two extra versions of file B add 3 + 3 = 6 MB. Total is 10 + 6 = 16 MB.