Sonarr and mono-sgen64 processes out of control


Occasionally, the Sonarr process will get out of control in Activity Monitor (increases to 120% or higher). If I try quitting from the web admin, the Sonarr process doesn’t quit, and then the mono-sgen64 process also goes really high, to about the same percentage. When this happens, the only thing I have been able to find to fix it is to reboot the entire computer.

Mac Mini running Sierra 10.12.6. Latest version of Sonarr and mono.


We need additional information and specific versions.

Sonarr version (exact version):
Mono version (if Sonarr is not running on Windows):
Trace logs:
(Make sure trace logging is enabled in settings and post the full log to hastebin/pastebin/dropbox/google drive or something similar, do not post them directly here. Post in .txt not .doc, .rtf or some other formatted document)
Description of issue:


Ok it just happened again … the Sonarr process has been stuck at 128.8% for the last several minutes. Here are the items you requested:

Sonarr version:
Mono version:
OS: macOS 10.12.6
Trace logs link:


Just checking in … did this info help?


The only thing in that log is Sonarr getting the history from NZBGet. With close to 900 items, Sonarr would need to process each one every minute or so. Hiding old history items (which reduces the information stored) may result in less of a hit.

Beyond that, old logs might show something else happening (processing files on disk, RSS Sync with lots of items).


Are you referring to hiding history items in Sonarr? Or in NZBGet? How do I do that?

I just checked the history in Sonarr and there are almost 16,000 items in the history. Should I clear that somehow? What are the implications of removing those history items?


NZBGet. Effectively it’s deleting it, but NZBGet retains some information on deleted history, offhand I’m not sure how best to do that in NZBGet.

No. Sonarr uses it’s history to check what it’s done in the past in some cases, there isn’t a way to remove/archive that history.


If you’re not interested in the dupe checking capabilities of NZBGet (I’m not), this is what works for me:

  • Dupecheck: No
  • KeepHistory: 5 days
  • in Sonarr/Radarr: Settings > Download Client > (show advanced settings) > enable Remove for both Completed Download Handling and Failed Download Handling

I rarely download things manually anymore, so this ensures the history of NZBGet stays nice and clean. On the off-chance that I do things myself, 5 days to remain in history is plenty of time because usually I’m waiting for that download to finish anyway so I do stuff with it as soon as it’s done and then delete it from the history as well.

So under normal operations, the history tab should always be empty. If there’s something in there, either it’s a manual download or something (sonarr/radarr) is not working properly (not processing finished downloads).


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