readers[i] = newBitrotReader(disk, copyPartsMetadata[i].Data, bucket, partPath, tillOffset, checksumAlgo,
					checksumInfo.Hash, erasure.ShardSize())
				prefer[i] = disk.Hostname() == ""

			}
			writers := make([]io.Writer, len(outDatedDisks))
			for i, disk := range outDatedDisks {
				if disk == OfflineDisk {
					continue
				}