The first method is to configure your client to download the files to a temporary directory and then copy them into their final location when the downloads are finished, provided that your client supports this.
The second method is to use
the [http:/ /vleu.net/shake/ ShAkE] tool to perform defragmentation by rewriting the files sequentially . Integrity verification should be done after running ShAkE to ensure that the file contents are identical to what they were before running ShAkE. Those using the ShAkE tool should be aware that ShAkE works by triggering copy on write for the entire file, which will cause files stored in snapshots to be stored twice. This can be exploited for verification purposes by calculating md5/sha1/sha256 checksums and comparing, but it is not otherwise desirable. Alternatively, verification can be performed with the bit torrent protocol.
In practice, defragmenting files obtained through bit torrent should only improve performance when the files are stored on magnetic storage and are subject to significant sequential read workloads after creation.