Block storage vs object storage vs file storage in HLD - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Differences in data access methods

Which storage type accesses data as fixed-size chunks called blocks, allowing low-level control and fast performance?

A Object storage

B File storage

C Cloud storage

D Block storage

💡 Hint

Think about storage used by databases and virtual machines.

Block storage divides data into blocks and manages them individually, enabling fast and flexible access. File storage manages data as files in folders, and object storage manages data as objects with metadata.

❓ Architecture

intermediate

Choosing storage for a photo sharing app

You are designing a photo sharing app where users upload images and metadata. Which storage type is best suited to store images with metadata and scale easily?

A Block storage for raw image data

B Object storage with metadata support

C File storage with hierarchical folders

D Local disk storage on user devices

💡 Hint

Consider storage that handles large amounts of unstructured data with metadata.

Object storage is ideal for storing images as objects with metadata and scales well for large datasets. File storage is less scalable and block storage is low-level and not metadata-aware.

❓ scaling

advanced

Scaling file storage for many users

A company uses file storage for shared documents. As users grow, performance drops due to many concurrent file accesses. What is the main limitation causing this?

A File storage uses a centralized metadata server causing bottlenecks

B Block storage cannot handle many files

C Object storage lacks metadata support

D File storage splits files into blocks causing overhead

💡 Hint

Think about how file systems manage file locations and access.

File storage relies on a centralized metadata server to manage file locations, which can become a bottleneck under heavy concurrent access, limiting scalability.

❓ tradeoff

advanced

Tradeoffs between block and object storage

Which statement correctly describes a tradeoff between block storage and object storage?

A Block storage is optimized for large files with metadata, object storage for small fixed-size blocks

B Block storage offers metadata and global namespace, object storage offers low-level control

C Block storage provides low-level fast access but lacks metadata, object storage supports metadata but has higher latency

D Block storage is cheaper and slower, object storage is expensive and faster

💡 Hint

Consider access speed and metadata capabilities.

Block storage provides fast, low-level access without metadata support. Object storage supports rich metadata and global namespace but has higher latency.

❓ estimation

expert

Estimating capacity for mixed storage system

A system stores 10 million files averaging 5 MB each in file storage, 2 million objects averaging 20 MB each in object storage, and 500 TB in block storage. What is the total approximate storage capacity needed?

A About 1.5 PB

B About 2 PB

C About 1 PB

D About 500 TB

💡 Hint

Calculate total size by multiplying counts and average sizes, then sum.

File storage: 10M * 5MB = 50 TB
Object storage: 2M * 20MB = 40 TB
Block storage: 500 TB
Total ≈ 590 TB, closest to About 1.5 PB option.

Practice

1. Which storage type splits data into fixed-size blocks and provides fast, low-level access?

easy

A. Block storage

B. Object storage

C. File storage

D. Cloud storage

Solution

1. Step 1: Understand block storage concept

   Block storage divides data into blocks and stores them separately for quick access.

2. Step 2: Compare with other storage types

   Object storage stores data as objects with metadata, and file storage organizes data in files and folders.

3. Final Answer:

   Block storage -> Option A

4. Quick Check:

   Block storage = fast block-level access [OK]

Hint: Blocks mean fast raw data access, not files or objects [OK]

Common Mistakes:

• Confusing object storage with block storage
• Thinking file storage splits data into blocks
• Assuming cloud storage is a type here

2. Which of the following correctly describes object storage?

easy

A. Stores data as blocks without metadata

B. Stores data as objects with metadata for easy retrieval

C. Organizes data in hierarchical files and folders

D. Splits data into fixed-size chunks for fast access

Solution

1. Step 1: Recall object storage features

   Object storage saves data as objects, each with metadata describing the data.

2. Step 2: Eliminate incorrect options

   Blocks without metadata describe block storage; hierarchical files describe file storage.

3. Final Answer:

   Stores data as objects with metadata for easy retrieval -> Option B

4. Quick Check:

   Object storage = objects + metadata [OK]

Hint: Objects always have metadata; blocks do not [OK]

Common Mistakes:

• Mixing block storage with object storage
• Thinking file storage uses metadata like objects
• Confusing hierarchical files with object storage

3. A company needs to store large amounts of unstructured data like images and videos with metadata for easy search. Which storage type fits best?

medium

A. Object storage for metadata and scalability

B. Block storage for fast raw access

C. File storage for hierarchical organization

D. Local disk storage for simplicity

Solution

1. Step 1: Analyze data type and requirements

   Unstructured data like images/videos benefit from metadata and scalability.

2. Step 2: Match storage type to needs

   Object storage supports metadata and scales well for large unstructured data sets.

3. Final Answer:

   Object storage for metadata and scalability -> Option A

4. Quick Check:

   Unstructured + metadata = Object storage [OK]

Hint: Metadata + large unstructured data = object storage [OK]

Common Mistakes:

• Choosing block storage for unstructured data
• Assuming file storage handles metadata well
• Picking local disk which lacks scalability

4. A developer tries to use file storage for a distributed app needing fast block-level access but experiences slow performance. What is the likely cause?

medium

A. File storage does not support hierarchical folders

B. Block storage cannot be used in distributed apps

C. File storage is not optimized for block-level raw access

D. Object storage lacks metadata support

Solution

1. Step 1: Understand file storage characteristics

   File storage organizes data in files and folders, optimized for sharing, not raw block access.

2. Step 2: Identify mismatch with app needs

   Fast block-level access requires block storage, not file storage, causing slow performance.

3. Final Answer:

   File storage is not optimized for block-level raw access -> Option C

4. Quick Check:

   File storage ≠ fast block access [OK]

Hint: File storage is for files, not fast block access [OK]

Common Mistakes:

• Believing block storage can't be used distributed
• Confusing object storage metadata with file storage
• Thinking file storage lacks folders

5. You are designing a scalable photo-sharing app. Users upload photos with tags and descriptions. Which storage type should you choose and why?

hard

A. Local disk storage, for simplicity and speed

B. File storage, to organize photos in folders by user

C. Block storage, for fast access to photo bytes

D. Object storage, to store photos with metadata and scale easily

Solution

1. Step 1: Analyze app requirements

   The app needs to store photos with tags/descriptions (metadata) and scale for many users.

2. Step 2: Match storage type to requirements

   Object storage supports metadata per object and scales well for large data and users.

3. Step 3: Evaluate other options

   Block storage is low-level without metadata; file storage is less scalable; local disk lacks scalability and reliability.

4. Final Answer:

   Object storage, to store photos with metadata and scale easily -> Option D

5. Quick Check:

   Photo app + metadata + scale = Object storage [OK]

Hint: Metadata + scale = object storage for apps [OK]

Common Mistakes:

• Choosing block storage ignoring metadata needs
• Assuming file storage scales well for many users
• Picking local disk for a cloud-scale app