Loki is not bad but PSA, don't use it with anything else than real AWS S3. The performance with Minio is awful (and can't be good, because of how minio works). Might be a bit better with Seaweedfs.
it simply stores objects as files on the disk. Then it distributes the chunks around the place (so you need to reassemble it when reading) and lastly, when you read the file, it's not O(1). There is some "discovery" process to locate the objects where the servers chat with each other rather than have the location stored somewhere and be O(1).