Deluge Forum

I use deluge to seed files located on nas (deluge itself is not on nas - it reads files over network), recently i got a connection with much faster upload speed (100Mbs vs 5Mbs i had before) and started seeding at fullspeed. But then i noticed that when i watch videos located on nas on my htpc sometimes video stutters/freezes occasionally. At first i didnt link it to deluged, but upon investigation i noticed something really weird - when seeding deluge reads significantly more data at much higher speed that you would expect from upload speed. When uploading at 100KB/s deluged reads 1-3MB/s (30 seconds average, 1s peaks could be 2-3x this), uploading at 2MB/s disk reads at 10-12MB/s, uploading at 10MB/s disk reads at 40-50MB/s. Considering that nas read speed is ~80MB/s you can see where freezes come from.

Whats going on here?

P.S. deluge 1.3.10 with libtorrent 0.15.10.0, i tried increasing deluge cash to 16384 (250MB if i am calculating correctly?) but it had no effect on this.

First step is to use a newer version of libtorrent.

Ok. I had build and installed 0.16.18.0. It did not alleviated the problem even a slightest.

One observation about a problem - it seems that "multiplication coefficient" greatly depends on a size of a torrents been uploaded - on <1GB torrents it is almost nonexistent, while on 150GB torrent it can reach 50x. Right now deluge is uploading two ~120GB torrents with upload speed in 150-200KB/s range - sustained disk read speed is ~5MB/s

Probably worth reading the libtorrent tuning docs: http://libtorrent.org/tuning.html (You can alter any session_settings with ltconfig plugin)

After some playing with libtorrent settings i mostly fixed this problem by setting use_read_cache to false. Deluge still reads at 2-3x upload speed, but at least not at 30x. Apparently something is terrible wrong with libtorrent read caching algorithm.

You can discuss that with libtorrent developer on the mailing list if you want, also the latest version of libtorrent is 1.0.3 and should work fine with Deluge.