This is the error what is so annoying and it appears so often for everyone, who downloads huge files.
In this tutorial I am gonna tell you how to fix / minimalize it.

Follow these steps:

1. Make sure you are using uTorrent 2.2.1, because that's the most stable and most allowed torrent client on every torrent site. You can download it from http://utorrent.hu/download/utorrent-2-2-1-2/
2. Open the uTorrent settings (CTRL+P)
3. Tick the preallocate files button and untick all the updating and data sending related things
4. Go to advanced settings
5. Set bt.prio_first_last_piece to true
6. Set diskio.coalesce_write_size to 8388608
7. Set diskio.flush_files to false
8. Set diskio.sparse_files to true
9. Go to cache settings
10. Tick the override default cache, and set the cache size to 368MB
11. Apply and save the settings
12. After restarting uTorrent you will see way less or maybe absolutely no disk overload issues anymore

If you have any questions, write a comment.
If you like my tutorial, please don't forget to leave a REP + LIKE