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MinIO supports keeping multiple “versions” of an object in a single bucket. Write operations which would normally overwrite an existing object instead result in the creation of a new versioned object. MinIO versioning protects from unintended overwrites and deletions while providing support for “undoing” a write operation. Bucket versioning also supports retention and archive policies.
MinIO generates a unique immutable ID for each object. If a
contains an object name which duplicates an existing object, MinIO does not
overwrite the “older” object. Instead, MinIO retains all object versions while
considering the most recently written “version” of the object as “latest”.
Applications retrieve the latest object version by default, but may retrieve
any other version in the history of that object. To view all versions of an
object or objects in a bucket, use the
mc ls --versions command.
By default, deleting an object does not remove all existing versions of
that object. Instead, MinIO places a “delete” marker for the object, such that
applications requesting only the latest object versions do not see the object.
Applications may retrieve earlier versions of that object. To completely
delete an object and its entire version history, use the
mc rm --versions command.
Enabling bucket versioning on a MinIO deployment requires that the deployment
have at least four disks. Specifically, Bucket Versioning depends on
Erasure Coding. For MinIO deployments that
meet the disk requirements, use the
mc version enable command to
enable versioning on a specific bucket.
mc version command may work on other S3-compatible services
depending on their implementation of and support for the AWS S3 API.
After enabling bucket versioning, MinIO begins generating version IDs for
new objects created in the bucket. MinIO does not iterate through existing
objects to generate version IDs. Existing unversioned objects in a versioned
bucket have a
null version ID.
You can suspend bucket versioning at any time using
mc version disable. MinIO retains all existing object versions. During
suspension, MinIO allows overwrites of any unversioned object. Applications
can continue referencing any existing object version.
You can later re-enable object versioning on the bucket. MinIO resumes
generating version IDs for new objects, and does not retroactively generate
version IDs for existing unversioned objects. MinIO lists unversioned
objects with a
null version ID.
MinIO version ID’s are DCE 1.1/RFC 4122-compliant Universally Unique Identifiers (UUID) version 4. Each UUID is a random 128-bit number intended to have a high likelihood of uniqueness over space and time, and that are computationally difficult to guess. UUID’s are globally unique that can be generated without contacting a global registration authority.
MinIO object version UUID’s are immutable after creation.
The following MinIO features require bucket versioning for functionality: