Versioning and Object Lifecycle

Yes, in Amazon S3, you can transition object versions between different storage classes, but the ability to do so depends on the versioning configuration of your bucket.

Here are the key points to understand when moving versions between storage classes in Amazon S3:

1. Versioning and Object Lifecycle

When versioning is enabled for an S3 bucket, every time you upload a new version of an object, S3 assigns it a unique version ID. These versions can be transitioned between storage classes as part of a lifecycle rule.

You can set lifecycle rules to transition both current and noncurrent versions of an object to different storage classes. Here’s a breakdown of how this works:

2. Transitioning Object Versions Between Storage Classes

You can transition the current version (the most recent version of the object) and the noncurrent versions (previous versions) to different storage classes using lifecycle policies.

Current Versions Transition:

You can create a rule that moves the most recent (current) version of an object to a different storage class after a certain period, such as moving objects to STANDARD_IA or GLACIER after a certain number of days.

Noncurrent Versions Transition:

You can also transition noncurrent versions (older versions of the object) to different storage classes or delete them after a set period.

3. Creating Lifecycle Policies for Version Transitions

Here’s how you can configure lifecycle rules for version transitions:

Example 1: Transition Current and Noncurrent Versions to Different Storage Classes

If you want to move the current version to STANDARD_IA after 30 days and move noncurrent versions to GLACIER after 60 days, you can define a lifecycle rule like this:

{
  "Rules": [
    {
      "ID": "Transition Current and Noncurrent Versions",
      "Status": "Enabled",
      "Transitions": [
        {
          "Days": 30,
          "StorageClass": "STANDARD_IA"
        }
      ],
      "NoncurrentVersionTransitions": [
        {
          "NoncurrentDays": 60,
          "StorageClass": "GLACIER"
        }
      ]
    }
  ]
}

This rule will:

• Transition the current version to STANDARD_IA after 30 days.
• Transition noncurrent versions (previous versions) to GLACIER after 60 days.

Example 2: Transition Noncurrent Versions to Another Storage Class

If you just want to transition noncurrent versions to GLACIER after 30 days without affecting the current version, you can use:

{
  "Rules": [
    {
      "ID": "Transition Noncurrent Versions Only",
      "Status": "Enabled",
      "NoncurrentVersionTransitions": [
        {
          "NoncurrentDays": 30,
          "StorageClass": "GLACIER"
        }
      ]
    }
  ]
}

4. Applying Lifecycle Rules Using AWS CLI

To apply a lifecycle policy via the AWS CLI, you can use the put-bucket-lifecycle-configuration command. Here’s an example to move noncurrent versions to GLACIER after 30 days:

aws s3api put-bucket-lifecycle-configuration --bucket BUCKET_NAME --lifecycle-configuration '{
    "Rules": [
        {
            "ID": "Transition Noncurrent Versions to Glacier",
            "Status": "Enabled",
            "NoncurrentVersionTransitions": [
                {
                    "NoncurrentDays": 30,
                    "StorageClass": "GLACIER"
                }
            ]
        }
    ]
}'

In this example:

• Replace BUCKET_NAME with the name of your S3 bucket.
• The rule transitions noncurrent versions to GLACIER after 30 days.

5. Supported Storage Classes for Transition

You can transition both current and noncurrent versions to the following storage classes:

• STANDARD (default)
• STANDARD_IA (Infrequent Access)
• ONEZONE_IA (One Zone-Infrequent Access)
• GLACIER (for archival)
• DEEP_ARCHIVE (for long-term archival)

6. Important Considerations:

• Versioning must be enabled: Transitions between storage classes apply to objects in versioned buckets.
• Lifecycle Rules for Current and Noncurrent Versions: You can specify different transition rules for current and noncurrent versions.
• Noncurrent Version Actions: These apply only to previous versions of an object, not the most recent version.

Summary:

• Yes, you can move versions (both current and noncurrent) between storage classes in S3 using lifecycle policies.
• You can automate the transition of current versions to cheaper storage like STANDARD_IA or GLACIER after a specific period, and also move older, noncurrent versions to archival storage (like GLACIER or DEEP_ARCHIVE) for cost savings.

Let me know if you’d like help with specific lifecycle policies or further examples!