Since a couple of days, maybe since upgrading to Deluge 2.1.1 from 2.0.5, I'm getting spammed with the following warning logs entries when downloading:
[WARNING ][deluge.core.torrentmanager :1621] on_alert_performance: *TORRENT NAME*: performance warning: the disk queue limit is too high compared to the cache size. The disk queue eats into the cache size, too_high_disk_queue_limit
I'm using the linuxserver/deluge:2.1.1 Docker image.
What i know is that cache_size is the amount of RAM you are telling to Deluge to use for torrents that are active. So lets say you have a torrent that is active usually it would do disk writes/reads. So to have less disk rights/reads you can crank up cache_size. This gives you faster speeds with downloads/uploads. I for example have like 2 GB of cache_size