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Reference Hardware
Object Deletion
Overview
This page summarizes how a DELETE operation affects objects depending on the configuration of the bucket that contains the object.
Any combination of the following factors may impact how DELETE operations function:
Permissions
MinIO uses a policy based access control system for access management.
The user or service account must provide the correct policy action and conditions to allow a DELETE for the bucket and object.
Unversioned Objects
When performing a DELETE operation on an object in a bucket that does not have versioning enabled, the operation is straightforward.
After verifying the user or service account has permission to perform the DELETE operation, MinIO permanently removes the object.
The user or service account requesting the delete action the action must have the s3:DeleteObject action permission for the bucket and object.
Versioned Objects
DELETE operations work differently when an object is versioned.
The user or service account must have the s3:DeleteObjectVersion action permission for the bucket and object.
Delete operations on the current version
A DELETE operation on a versioned object that does not specify a version UUID results in the creation of a DeleteMarker placed as the head of the object.
In this scenario, MinIO does not actually remove the object or any of its versions from the disk.
All existing versions of the object remain available to access by specifying the version’s UUID.
When a DeleteMarker is the head for the object, MinIO does not serve the object for GET requests that do not specify a version ID.
Instead, MinIO returns a 404-like response.
You can find the UUID of object versions with mc ls --versions.
To remove the current version of the object from the drive, find the UUID of the version, and then use mc rm --version-id=UUID ... to delete the current version.
In this scenario, the immediately preceding version of the object then becomes the current version of the object served for GET requests of the object with no UUID specified.
Warning
Specifying a version-id in a DELETE operation is irreversible.
MinIO removes the specified version from the drive and cannot retrieve it.
Delete operations on a prior version
To delete prior versions of an object, specify the version’s UUID.
You can retrieve the version UUID with mc ls --versions.
When the DELETE request specifies a version-id and the user has the correct permissions to delete the object version`, MinIO permanently removes the specified version from the drive.
Warning
Specifying a version-id in a DELETE operation is irreversible.
MinIO removes the specified version from the drive and cannot retrieve it.
Delete all versions
Use mc rm --versions to delete all versions of an object.
This is irreversible.
Lifecycle Management Expiration
You can define one or more lifecycle management expiration rule(s) to expire objects after a certain version number count or a certain period of time. When more versions exist than the rule specifies, or when a version is older than specified, MinIO permanently removes the object version from the drive.
These rules rely on the scanner to process the rule on the bucket.
The scanner operates as a lower priority continuous process where READ and WRITE actions are preferred.
Because of this, object versions that meet the requirements for expiration may not immediately be removed from MinIO.
See the scanner page for more details on how the scanner works and configuration options.
DeleteMarkers are their own objects.
Lifecycle rules can remove DeleteMarkers that are the only remaining versions of their objects.
Retained Objects
MinIO protects objects subject to a locking rule from being overwritten or deleted. These rules require that objects be retained until either the rule expires or is removed.
DELETE operations on locked objects without a specified version result in the creation of a DeleteMarker for the object.
However, the object versions themselves are retained as required by the lock.
DELETE operations that specify an object version are subject to the retention rules.
MinIO protects object versions subject to a lock from being overwritten or deleted until the lock expires or is removed.
Replicated Objects
Replication duplicates objects from one location to another. MinIO supports replication at the bucket level or the cluster (“site”) level.
Delete operations may or may not replicate, depending on the type of replication and how the replication is configured.
Site Replication
For clusters with multi-site replication enabled, MinIO replicates all delete operations performed on any cluster to each of the other clusters in the peer group.
Delete behavior on any single peer follows the same processes as any MinIO deployment.
Bucket Replication
With bucket replication, MinIO supports replicating delete operations between a source bucket and a configured remote bucket. MinIO synchronizes deleting specific object versions and new delete markers. Delete operation replication uses the same replication process as all other replication operations.
MinIO requires explicitly enabling versioned deletes and delete marker replication.
Use the mc replicate add --replicate field to specify either delete and delete-marker or both to enable versioned deletes and delete marker replication, respectively.
To enable both, specify both strings using a comma separator: delete,delete-marker.
For delete marker replication, MinIO begins the replication process after a delete operation creates the delete marker.
MinIO uses the X-Minio-Replication-DeleteMarker-Status metadata field for tracking delete marker replication status.
In active-active replication configurations, MinIO may produce duplicate delete markers if both clusters concurrently create a delete marker for an object or if one or both clusters were down before the replication event synchronized.
For replicating the deletion of a specific object version, MinIO marks the object version as PENDING until replication completes.
Once the remote target deletes that object version, MinIO deletes the object version on the source.
While this process ensures near-synchronized version deletion, it may result in listing operations returning the object version after the initial delete operation.
MinIO uses the X-Minio-Replication-Delete-Status for tracking delete version replication status.
MinIO only replicates explicit client-driven delete operations. MinIO does not replicate objects deleted by lifecycle management expiration rules. For active-active configurations, set the same expiration rules on all of of the replication buckets to ensure consistent application of object expiration.
MinIO Trims Empty Object Prefixes on Source and Remote Bucket
If a delete operation removes the last object in a bucket prefix, MinIO recursively removes each empty part of the prefix up to the bucket root.
MinIO only applies the recursive removal to prefixes created implicitly as part of object write operations.
MinIO does not recursively remove prefixes created using an explicit directory creation command, such as mc mb.
If a replication rule enables replication delete operations, the replication process also applies the implicit prefix trimming behavior on the destination MinIO cluster.
For example, consider a bucket photos with the following object prefixes:
photos/2021/january/myphoto.jpg//2021/january/created implicitly based on the object namephotos/2021/february/myotherphoto.jpg//2021/february/created implicitly based on the object namephotos/NYE21/NewYears.jpg//NYE21/explicitly created in the bucket
photos/NYE21 is the only prefix explicitly created using mc mb.
All other prefixes were implicitly created as part of writing the object located at that prefix.
A command removes
myphoto.jpg. MinIO automatically trims the empty/january/prefix.A command then removes the
myotherphoto.jpg. MinIO automatically trims the/february/prefix and the now-empty/2021prefix.A command removes the
NewYears.jpgobject. MinIO leaves the/NYE21/prefix remains in place since it was explicitly created.
