edjalmo
I have restricted Jackett memory usage to MemoryHigh=125M and MemoryMax=150M in system.d.
To activate this restriction on Rasberry Pi, add cgroup_enable=memory at the end of /flash/cmdline.txt
Please let me know if you can activate memory management and if MemoryHigh and MemoryMax are appropriate for Jackett
vpeter Thank you for your help with this
So, when I wake up today and check my pi it was freezed. I reboot it and this message show up (image 1).
I left it to see if it repaired by itself and returned to normal, but some time has passed and the system still showing this (image 2).
I think I'll have to rewrite LibreELEC, install everything and make all the settings from scratch. I should have made a backup 
But for the record: the system ran from 10 a.m. to 3:30 p.m. (when the system freezes).
At midnight I checked the memory usage and rss sync. The memory usage was 86%. The rss sync of sonarr/radarr and everything was okay. I think this limit is adequade (at least for who those use 3 indexers like me).
I was runing sonarr, radarr, bazarr, jackett and transmission. My Transmission is configure to only download during at dawn.
I think if I was not using the bazarr this would not have happened. Or maybe a reboot at 12 a.m solve this.
Is much complicate using all this on pi, unfortunately.
When I finished configuring the whole system, I'll test again and tell the new results.
Thanks for helping!