It seems that my QNAP HS-453DX with 4Gb RAM running the latest updated software has issues I haven’t seen before.
After extended listening (I usually see this error after many hours), memory usage for the Roon server app on the NAS goes above 2GB, which means it uses up all the total available system memory. In such a scenario it often happens that playback stops, skips tracks, reports media loading slowly, network issues etc. Before I haven’t seen memory usage above 1GB. Note that memory usage in itself is correlated but is not a sure trigger for the problems.
However, I must add, that sometime along the way I have also started using DSP for upsampling to DSD256 and EQ-ing for my Mojo + headphones, which also has an impact. However, 4GB should be enough for this too. CPU usage is usually now 40-60%, but that is also OK, I don’t really use the NAS for anything else.
Also, Roon memory usage is very inconsistent. Sometimes it goes up to 2.06Gb, sometimes it goes down to 1.6, 1.2. Also, it does not care that much in cases when I try to do something on the NAS if other apps are running, it just seem to reduce the memory footprint and it does not seem to effect playback. I am just guessing here, but as I always find something updated or done on the NAS when I check after Roon manifests this behaviour, it gives me the impression that Roon Server has issues managing memory (or even CPU?) when the OS is trying to something automatically instead of me doing it manually. It is certainly not a general performance issue (although this specific NAS is below recommended specs) as when I do anythinig manually I cannot force Roon Server to screw up.