Object Versioning

S4 supports S3-compatible object versioning. When enabled, every overwrite or delete creates a new version instead of replacing the previous data. This allows you to preserve, retrieve, and restore any previous version of an object.

Versioning States

A bucket can be in one of three versioning states:

Once versioning is enabled on a bucket, it cannot be disabled — only suspended.

Enable Versioning

aws s3api put-bucket-versioning \
  --bucket mybucket \
  --versioning-configuration Status=Enabled \
  --endpoint-url http://localhost:9000

Check Versioning Status

aws s3api get-bucket-versioning \
  --bucket mybucket \
  --endpoint-url http://localhost:9000

Upload Multiple Versions

Each PUT to the same key creates a new version:

# Version 1
echo "version 1" | aws s3api put-object \
  --bucket mybucket --key file.txt --body - \
  --endpoint-url http://localhost:9000

# Version 2
echo "version 2" | aws s3api put-object \
  --bucket mybucket --key file.txt --body - \
  --endpoint-url http://localhost:9000

Both PUT responses include an x-amz-version-id header with the unique version ID.

List All Versions

aws s3api list-object-versions \
  --bucket mybucket \
  --prefix file.txt \
  --endpoint-url http://localhost:9000

Returns all versions and delete markers for matching keys.

Get a Specific Version

aws s3api get-object \
  --bucket mybucket \
  --key file.txt \
  --version-id "ff495d34-c292-4af4-9d10-e186272010ed" \
  output.txt \
  --endpoint-url http://localhost:9000

Delete Behavior

Simple Delete (Creates Delete Marker)

aws s3api delete-object \
  --bucket mybucket \
  --key file.txt \
  --endpoint-url http://localhost:9000

This does not remove data. It creates a delete marker — a special version that makes the object appear deleted. A subsequent GET returns 404.

Permanently Delete a Version

aws s3api delete-object \
  --bucket mybucket \
  --key file.txt \
  --version-id "ff495d34-c292-4af4-9d10-e186272010ed" \
  --endpoint-url http://localhost:9000

Restore a Deleted Object

Remove the delete marker to restore the most recent version:

aws s3api delete-object \
  --bucket mybucket \
  --key file.txt \
  --version-id "<delete-marker-version-id>" \
  --endpoint-url http://localhost:9000

Suspend Versioning

aws s3api put-bucket-versioning \
  --bucket mybucket \
  --versioning-configuration Status=Suspended \
  --endpoint-url http://localhost:9000

When suspended, new objects are stored with a null version ID, but existing versions remain accessible.