deluge excessive disk reads

[Harkonnen]

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.

[Cas]

First step is to use a newer version of libtorrent.

[Harkonnen]

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

[Cas]

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

[Harkonnen]

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.

[Cas]

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.