`xl.meta` is a new self describing backend format used by MinIO to support AWS S3 compatible versioning.
This file is the source of truth for each `version` at rest. `xl.meta` is a msgpack file serialized from a
well defined data structure. To understand `xl.meta` here are the few things to start with

`xl.meta` carries first 8 bytes an XL header which describes the current format and the format version,

is stored under the `bucket/prefix` specified in the tier configuration with a custom name derived from a randomly generated uuid - e.g. `0b/c4/0bc4fab7-2daf-4d2f-8e39-5c6c6fb7e2d3`. The first two prefixes are characters 1-2,3-4 from the uuid. This format allows tiering to any cloud irrespective of whether the cloud in question supports versioning. The reference to the transitioned object name and transitioned tier is stored as part of the internal metadata for the object (or its version) on MinIO....