// Object Operations

func countOnlineDisks(onlineDisks []StorageAPI) (online int) {
	for _, onlineDisk := range onlineDisks {
		if onlineDisk != nil && onlineDisk.IsOnline() {
			online++
		}
	}
	return online
}

// CopyObject - copy object source object to destination object.
// if source object and destination object are same we only
// update metadata.

		for _, disk := range onlineDisks {
			if disk != nil && disk.IsOnline() {
				continue
			}
			er.addPartial(bucket, object, fi.VersionID)
			break
		}
	}

	for i := range len(onlineDisks) {
		if onlineDisks[i] != nil && onlineDisks[i].IsOnline() {
			// Object info is the same in all disks, so we can pick
			// the first meta from online disk
			fi = partsMetadata[i]
			break
		}
	}