Extra metadata maintained internally in `xl.meta` for a transitioned object

```
...
        "MetaSys": {
          "x-minio-internal-transition-status": "Y29tcGxldGU=",
          "x-minio-internal-transition-tier": "R0NTVElFUjE=",

	}
	return opts
}

// SetTransitionState sets ILM transition related information from given info.
func (os *objSweeper) SetTransitionState(info TransitionedObject) {
	os.TransitionTier = info.Tier
	os.TransitionStatus = info.Status
	os.RemoteObject = info.Name
	os.TransitionVersionID = info.VersionID
}

// shouldRemoveRemoteObject determines if a transitioned object should be

--restore-request Days=3
```

### 4.1 Monitoring transition events

`s3:ObjectTransition:Complete` and `s3:ObjectTransition:Failed` events can be used to monitor transition events between the source cluster and transition tier. To watch lifecycle events, you can enable bucket notification on the source bucket with `mc event add`  and specify `--event ilm` flag.

Note that transition event notification is a MinIO extension.

## Explore Further

sleep 10s

## Add warm tier
./mc ilm tier add minio sitea WARM-TIER --endpoint http://localhost:9004 --access-key minioadmin --secret-key minioadmin --bucket bucket

## Add ILM rules
./mc ilm add sitea/bucket --transition-days 0 --transition-tier WARM-TIER
./mc ilm rule list sitea/bucket

./mc cp README.md sitea/bucket/README.md

until $(./mc stat sitea/bucket/README.md --json | jq -r '.metadata."X-Amz-Storage-Class"' | grep -q WARM-TIER); do

  optional int64 observedGeneration = 3;

  // Last time the condition transitioned from one status to another.
  // +required
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastTransitionTime = 4;

  // The reason for the condition's last transition.
  // +required
  optional string reason = 5;

  // A human readable message indicating details about the transition.
  // +required
  optional string message = 6;
}

## TODO

- Richer progress UI is not present at the moment, this will be addressed in subsequent releases. Currently however a RATE of data transfer and usage increase is displayed via `mc`.

	if j.Type == DeleteType {
		return j.DeleteMarker.FreeVersion()
	}
	return false
}

// AddFreeVersion adds a free-version if needed for fi.VersionID version.
// Free-version will be added if fi.VersionID has transitioned.
func (x *xlMetaV2) AddFreeVersion(fi FileInfo) error {
	var uv uuid.UUID
	var err error
	switch fi.VersionID {
	case "", nullVersionID:
	default:
		uv, err = uuid.Parse(fi.VersionID)
		if err != nil {

  // Last time the condition transitioned from one status to another.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastTransitionTime = 4;

  // Unique, one-word, CamelCase reason for the condition's last transition.
  // +optional
  optional string reason = 5;

  // Human-readable message indicating details about last transition.
  // +optional
  optional string message = 6;
}

			expectedErr: errInvalidStorageClass,
		},
		{
			// no transition rule

  // timestamp for the last update to this condition
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastUpdateTime = 4;

  // lastTransitionTime is the time the condition last transitioned from one status to another.
  // If unset, when a new condition type is added or an existing condition's status is changed,
  // the server defaults this to the current time.
  // +optional