S3 storage classes (Standard, IA, Glacier) in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the AWS S3 Standard storage class used for?

The S3 Standard storage class is used for frequently accessed data that requires high durability, availability, and low latency. It is ideal for active data and websites.

beginner

What does the S3 Infrequent Access (IA) storage class offer?

S3 IA is for data that is accessed less often but still needs to be quickly available when requested. It offers lower storage costs than Standard but charges for retrieval.

beginner

Describe the main use case for the S3 Glacier storage class.

S3 Glacier is designed for long-term archival storage where data is rarely accessed. It offers very low storage costs but retrieval can take minutes to hours.

beginner

Which S3 storage class provides the fastest data retrieval?

The S3 Standard storage class provides the fastest data retrieval with low latency and high throughput.

intermediate

What is a key cost difference between S3 Standard and S3 IA?

S3 IA has lower storage costs than Standard but charges a fee each time data is retrieved, making it cost-effective for infrequent access.

Which S3 storage class is best for data that is accessed frequently?

A S3 Infrequent Access

B S3 Glacier

C S3 Standard

D S3 One Zone-IA

S3 Standard is optimized for frequent access with high availability and low latency.

What is a characteristic of S3 Glacier storage?

A Instant data retrieval

B No retrieval fees

C High storage cost with frequent access

D Low storage cost with delayed retrieval

S3 Glacier offers very low storage costs but retrieval can take minutes to hours.

Which S3 storage class charges retrieval fees?

A S3 Infrequent Access

B Both B and C

C S3 Standard-IA

D S3 Standard

Both S3 Infrequent Access and Standard-IA charge fees when data is retrieved.

If you want to store backup data that you rarely access but want to keep for years, which storage class is best?

A S3 Glacier

B S3 Infrequent Access

C S3 Standard

D S3 Intelligent-Tiering

S3 Glacier is designed for long-term archival with low cost and infrequent access.

Which storage class offers the highest availability and durability for active data?

A S3 Standard

B S3 Glacier

C S3 One Zone-IA

D S3 Intelligent-Tiering

S3 Standard provides 99.99% availability and 99.999999999% durability for active data.

Explain the differences between S3 Standard, S3 Infrequent Access, and S3 Glacier storage classes.

Think about how often you access the data and how fast you need it.

When would you choose S3 Glacier over S3 Standard or IA?

Consider backup or archival scenarios.

Practice

1. Which Amazon S3 storage class is best for data that you access frequently and need immediately?

easy

A. GLACIER

B. STANDARD_IA (Infrequent Access)

C. ONEZONE_IA

D. STANDARD

Solution

1. Step 1: Understand S3 storage classes purpose

   STANDARD is designed for frequently accessed data with low latency.

2. Step 2: Compare with other classes

   STANDARD_IA and GLACIER are for less frequent access and have retrieval delays.

3. Final Answer:

   STANDARD -> Option D

4. Quick Check:

   Frequent access = STANDARD [OK]

Hint: Frequent use? Pick STANDARD for fastest access [OK]

Common Mistakes:

• Choosing GLACIER for frequent access
• Confusing STANDARD_IA with STANDARD
• Ignoring retrieval delays in GLACIER

2. Which of the following is the correct way to specify the STANDARD_IA storage class in an AWS CLI command to upload a file?

easy

A. aws s3 cp file.txt s3://bucket/ --storage-class=STANDARDIA

B. aws s3 cp file.txt s3://bucket/ --storageclass STANDARD_IA

C. aws s3 cp file.txt s3://bucket/ --storage-class STANDARD_IA

D. aws s3 cp file.txt s3://bucket/ --storage-class=STANDARD-IA

Solution

1. Step 1: Recall AWS CLI syntax for storage class

   The correct option uses '--storage-class' with underscore and exact class name.

2. Step 2: Check each option for syntax errors

   aws s3 cp file.txt s3://bucket/ --storage-class STANDARD_IA matches correct syntax; others have typos or wrong format.

3. Final Answer:

   aws s3 cp file.txt s3://bucket/ --storage-class STANDARD_IA -> Option C

4. Quick Check:

   Correct flag and class name = aws s3 cp file.txt s3://bucket/ --storage-class STANDARD_IA [OK]

Hint: Use '--storage-class' exactly with underscore [OK]

Common Mistakes:

• Misspelling the flag as '--storageclass'
• Using dashes instead of underscores
• Omitting the space after the flag

3. You upload a 1 GB file to S3 using the GLACIER storage class. What happens when you try to access the file immediately after upload?

medium

A. The file is instantly available for download.

B. The file is available after a retrieval delay of several hours.

C. The file is deleted automatically after 24 hours.

D. The file is available only if you pay an extra fee upfront.

Solution

1. Step 1: Understand GLACIER retrieval behavior

   GLACIER stores data for long-term archiving with retrieval delays of hours.

2. Step 2: Check immediate access options

   Immediate access is not possible; retrieval requires a job that takes time.

3. Final Answer:

   The file is available after a retrieval delay of several hours. -> Option B

4. Quick Check:

   GLACIER retrieval delay = hours [OK]

Hint: GLACIER files need hours to retrieve, not instant [OK]

Common Mistakes:

• Assuming instant access like STANDARD
• Thinking files auto-delete after upload
• Believing extra upfront fees enable instant access

4. A user tries to upload a file to S3 with the command: aws s3 cp data.csv s3://mybucket/ --storage-class GLACIER but gets an error. What is the likely cause?

medium

A. GLACIER is not a valid storage class for direct upload via this command.

B. The bucket name is invalid.

C. The file data.csv does not exist locally.

D. The AWS CLI version does not support storage classes.

Solution

1. Step 1: Understand GLACIER upload restrictions

   GLACIER storage class cannot be used directly in 'aws s3 cp' uploads; use GLACIER via lifecycle or multipart upload.

2. Step 2: Check other options

   Bucket name and file existence errors produce different messages; CLI supports storage classes.

3. Final Answer:

   GLACIER is not a valid storage class for direct upload via this command. -> Option A

4. Quick Check:

   Direct upload with GLACIER = error [OK]

Hint: GLACIER needs lifecycle or special upload, not direct CLI copy [OK]

Common Mistakes:

• Assuming GLACIER can be set directly on upload
• Ignoring file existence errors
• Blaming bucket name without checking

5. You want to store 10 TB of backup data that you rarely access but must keep for years. You want to minimize cost but still be able to retrieve data within a few hours if needed. Which S3 storage class should you choose and why?

hard

A. STANDARD_IA, because it balances lower cost with quick access.

B. STANDARD, because it offers instant access despite higher cost.

C. GLACIER, because it is the cheapest but retrieval takes days.

D. GLACIER INSTANT RETRIEVAL, because it offers low cost and milliseconds access.

Solution

1. Step 1: Analyze access frequency and retrieval time needs

   Data is rarely accessed but must be retrievable within hours, not instantly.

2. Step 2: Compare storage classes for cost and retrieval speed

   STANDARD_IA offers lower cost than STANDARD and retrieval in milliseconds to seconds; GLACIER has longer retrieval times.

3. Final Answer:

   STANDARD_IA, because it balances lower cost with quick access. -> Option A

4. Quick Check:

   Rare access + quick retrieval = STANDARD_IA [OK]

Hint: Rare access + hours retrieval? Pick STANDARD_IA [OK]

Common Mistakes:

• Choosing GLACIER despite slow retrieval
• Picking STANDARD and paying too much
• Confusing GLACIER INSTANT RETRIEVAL (not standard GLACIER)