Thank you for your answers.
Yes, I read about how ZRAM works. However, my problem was that the RAM drive got filled up within minutes, not allowing the creation of any folder or additional log file. Consequently, amanda backup did not run properly.
I still think that in my case all information is logged three times. Below you find some snippets from the tail output of the different log files.
Disabling the logging in OpenHAB worked, such that there is not much information in events.log and openhab.log, now.
Thanks!
syslog:
Jul 21 07:42:46 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:42:46: MQTT publish: topic âzigbee2mqtt/WindowSensor02â, payload â{âbatteryâ:100,âvoltageâ:3005,âcontactâ:false,âlinkqualityâ:81}â
Jul 21 07:42:52 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:42:52: MQTT publish: topic âzigbee2mqtt/WindowSensor02â, payload â{âbatteryâ:100,âvoltageâ:3005,âcontactâ:true,âlinkqualityâ:76}â
Jul 21 07:45:01 openhab CRON[17994]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Jul 21 07:46:25 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:46:25: MQTT publish: topic âzigbee2mqtt/OsramPlug01â, payload â{âstateâ:âOFFâ,âlinkqualityâ:102,âupdate_availableâ:false}â
Jul 21 07:51:27 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:51:27: MQTT publish: topic âzigbee2mqtt/WindowSensor01â, payload â{âbatteryâ:86,âvoltageâ:2975,âcontactâ:false,âlinkqualityâ:2}â
Jul 21 07:55:01 openhab CRON[18239]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Jul 21 07:57:22 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:57:22: MQTT publish: topic âzigbee2mqtt/WindowSensor03â, payload â{âbatteryâ:100,âvoltageâ:3015,âcontactâ:true,âlinkqualityâ:0}â
Jul 21 08:01:33 openhab influxd[604]: ts=2020-07-21T06:01:33.401162Z lvl=info msg=âRetention policy deletion check (start)â log_id=0O7RCNL0000 service=retention trace_id=0O7~FcrG000 op_name=retention_delete_check op_event=start
Jul 21 08:01:33 openhab influxd[604]: ts=2020-07-21T06:01:33.401450Z lvl=info msg=âRetention policy deletion check (end)â log_id=0O7RCNL0000 service=retention trace_id=0O7~FcrG000 op_name=retention_delete_check op_event=end op_elapsed=0.342ms
Jul 21 08:05:01 openhab CRON[18462]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Jul 21 08:11:20 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 08:11:20: MQTT publish: topic âzigbee2mqtt/WindowSensor04â, payload â{âbatteryâ:100,âvoltageâ:3025,âcontactâ:true,âlinkqualityâ:28}â
daemon.log:
Jul 21 07:42:46 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:42:46: MQTT publish: topic 'zigbee2mqtt/WindowSensor02', payload '{"battery":100,"voltage":3005,"contact":false,"linkquality":81}'
Jul 21 07:42:52 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:42:52: MQTT publish: topic 'zigbee2mqtt/WindowSensor02', payload '{"battery":100,"voltage":3005,"contact":true,"linkquality":76}'
Jul 21 07:46:25 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:46:25: MQTT publish: topic 'zigbee2mqtt/OsramPlug01', payload '{"state":"OFF","linkquality":102,"update_available":false}'
Jul 21 07:51:27 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:51:27: MQTT publish: topic 'zigbee2mqtt/WindowSensor01', payload '{"battery":86,"voltage":2975,"contact":false,"linkquality":2}'
Jul 21 07:57:22 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 07:57:22: MQTT publish: topic 'zigbee2mqtt/WindowSensor03', payload '{"battery":100,"voltage":3015,"contact":true,"linkquality":0}'
Jul 21 08:01:33 openhab influxd[604]: ts=2020-07-21T06:01:33.401162Z lvl=info msg="Retention policy deletion check (start)" log_id=0O7RCNL0000 service=retention trace_id=0O7~FcrG000 op_name=retention_delete_check op_event=start
Jul 21 08:01:33 openhab influxd[604]: ts=2020-07-21T06:01:33.401450Z lvl=info msg="Retention policy deletion check (end)" log_id=0O7RCNL0000 service=retention trace_id=0O7~FcrG000 op_name=retention_delete_check op_event=end op_elapsed=0.342ms
Jul 21 08:11:20 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 08:11:20: MQTT publish: topic 'zigbee2mqtt/WindowSensor04', payload '{"battery":100,"voltage":3025,"contact":true,"linkquality":28}'
Jul 21 08:23:26 openhab npm[603]: #033[32mzigbee2mqtt:info #033[39m 2020-07-21 08:23:26: MQTT publish: topic 'zigbee2mqtt/WindowSensor02', payload '{"battery":100,"voltage":3005,"contact":false,"linkquality":78}'