what I can see :
log to alda.log started yesterday evening, without any power lost, but data are not there in openhab.log :
and also in alda.log I can see data from 19:20
after reboot instruction I can see this:
All I can say is that OH isn’t going to delete file willy nilly.
If your openhab.log is completely empty, you’ve messed up your log4j2.xml file and somehow disabled/broke the config for that logger/appender.
It’s weird that only the alda log rotated which additionally points to problems with the log4j2.xml file.
But the rotated file looks to be empty so 
I compared my log4j2.xml with log4j2.xml on the network and they are same, only in my is added what is posted above.
Strange
When weird inexplicable stuff happens, one always has to wonder if the SD card has worn out. A system behaves in strange and weird ways when that happens. For example, I once had one fail and I discovered it because log files I’ve manually deleted get “restored” when I rebooted.
my card isn’t so old and using eMMC card
we will see.
Will try next reboot
ok after next reboot :
data from alda.log and also openhab.log are lost
File system isn’t full? It’s the last thing I can think of. If it’s not full 
Your machine is simply not healthy and it’s unlikely I at least will be able to remotely diagnose it.
What’s interesting though is this time and the previous time is that openhab.log isn’t empty.
Yes, I can see a startup data :
2023-06-01 21:19:19.237 [INFO ] [.core.internal.i18n.I18nProviderImpl] - Time zone set to 'Europe/Prague'.
2023-06-01 21:19:19.314 [INFO ] [.core.internal.i18n.I18nProviderImpl] - Location set to '52.28014296840402,17.1792283415794374'.
2023-06-01 21:19:19.317 [INFO ] [.core.internal.i18n.I18nProviderImpl] - Locale set to 'cs_CZ'.
2023-06-01 21:19:35.331 [INFO ] [.core.model.lsp.internal.ModelServer] - Started Language Server Protocol (LSP) service on port 5007
2023-06-01 21:19:39.713 [INFO ] [e.automation.internal.RuleEngineImpl] - Rule engine started.
2023-06-01 21:19:39.837 [WARN ] [internal.things.EBusTypeProviderImpl] - eBUS command boiler.control.setopdata only contains a setter channel!
2023-06-01 21:19:40.194 [INFO ] [ing.ebus.internal.EBusHandlerFactory] - Use eBUS binding 3.2.14 [eBUS core: 1.1.8, eBUS configuration: 1.1.6]
2023-06-01 21:19:40.197 [INFO ] [ing.ebus.internal.EBusHandlerFactory] - eBUS core -> timestamp 202112291704, commit: #768d88c, build-no: #null
2023-06-01 21:19:40.199 [INFO ] [ing.ebus.internal.EBusHandlerFactory] - eBUS configuration -> timestamp 202112291722, commit: #7d79e24, build-no: #null
2023-06-01 21:19:40.436 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Bridge is not online yet ...
2023-06-01 21:19:40.460 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Bridge is not online yet ...
2023-06-01 21:19:40.482 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Bridge is not online yet ...
2023-06-01 21:19:40.499 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Bridge is not online yet ...
2023-06-01 21:19:40.517 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Bridge is not online yet ...
2023-06-01 21:19:40.603 [INFO ] [al.EBusSerialBuildInSerialConnection] - Use openhab build-in serial driver .................................................................
2023-06-01 21:19:40.705 [INFO ] [ng.ebus.internal.handler.EBusHandler] - (Re)Initialize all eBUS pollings for ebus:vrc700_hc1:94aed4019b:15 ...
2023-06-01 21:19:40.705 [INFO ] [ng.ebus.internal.handler.EBusHandler] - (Re)Initialize all eBUS pollings for ebus:vrc700_general:94aed4019b:15 ...
2023-06-01 21:19:40.708 [INFO ] [ng.ebus.internal.handler.EBusHandler] - (Re)Initialize all eBUS pollings for ebus:vrc700_zone2:94aed4019b:15 ...
2023-06-01 21:19:40.720 [INFO ] [ng.ebus.internal.handler.EBusHandler] - (Re)Initialize all eBUS pollings for ebus:vrc700_zone1:94aed4019b:15 ...
2023-06-01 21:19:40.724 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.energy_sum" every 60 sec. (initial delay 6 sec.)
2023-06-01 21:19:40.726 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hc1.flow_setpoint" every 60 sec. (initial delay 6 sec.)
2023-06-01 21:19:40.727 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z1.room_temp" every 60 sec. (initial delay 6 sec.)
2023-06-01 21:19:40.728 [INFO ] [ng.ebus.internal.handler.EBusHandler] - (Re)Initialize all eBUS pollings for ebus:vrc700_hwc:94aed4019b:15 ...
2023-06-01 21:19:40.732 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z2.day_setpoint" every 60 sec. (initial delay 6 sec.)
2023-06-01 21:19:40.735 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.bank_holiday_start" every 60 sec. (initial delay 2 sec.)
2023-06-01 21:19:40.740 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z1.room_map" every 60 sec. (initial delay 2 sec.)
2023-06-01 21:19:40.740 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hc1.summer_limit" every 60 sec. (initial delay 2 sec.)
2023-06-01 21:19:40.741 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hwc.flow_temp" every 60 sec. (initial delay 6 sec.)
2023-06-01 21:19:40.746 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hc1.flow_temp" every 60 sec. (initial delay 16 sec.)
2023-06-01 21:19:40.747 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.energy_sum_last_month_hwc" every 60 sec. (initial delay 16 sec.)
2023-06-01 21:19:40.749 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z2.sf_mode" every 60 sec. (initial delay 2 sec.)
2023-06-01 21:19:40.756 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.bank_holiday_end" every 60 sec. (initial delay 13 sec.)
2023-06-01 21:19:40.756 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hwc.setpoint" every 60 sec. (initial delay 2 sec.)
2023-06-01 21:19:40.756 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z2.valve_status" every 60 sec. (initial delay 16 sec.)
2023-06-01 21:19:40.758 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hc1.heating_curve" every 60 sec. (initial delay 13 sec.)
2023-06-01 21:19:40.770 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.time" every 60 sec. (initial delay 4 sec.)
2023-06-01 21:19:40.780 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z2.quick_veto" every 60 sec. (initial delay 13 sec.)
2023-06-01 21:19:40.781 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hc1.status" every 60 sec. (initial delay 4 sec.)
2023-06-01 21:19:40.782 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z2.night_setpoint" every 60 sec. (initial delay 4 sec.)
2023-06-01 21:19:40.782 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hwc.sf_mode" every 60 sec. (initial delay 16 sec.)
2023-06-01 21:19:40.783 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.lock_time" every 60 sec. (initial delay 1 sec.)
2023-06-01 21:19:40.785 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.date" every 60 sec. (initial delay 10 sec.)
2023-06-01 21:19:40.785 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z2.op_mode" every 60 sec. (initial delay 1 sec.)
2023-06-01 21:19:40.786 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "z2.actual_setpoint" every 60 sec. (initial delay 10 sec.)
2023-06-01 21:19:40.787 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hc1.max_flow_temp" every 60 sec. (initial delay 1 sec.)
2023-06-01 21:19:40.789 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Unable to create raw polling telegram for "gen.bc_temp_outside" !
2023-06-01 21:19:40.789 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hwc.storage_temp" every 60 sec. (initial delay 13 sec.)
2023-06-01 21:19:40.791 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hc1.pump_status" every 60 sec. (initial delay 10 sec.)
2023-06-01 21:19:40.791 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "hwc.op_mode" every 60 sec. (initial delay 4 sec.)
2023-06-01 21:19:40.793 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.cylider_charging_time" every 60 sec. (initial delay 5 sec.)
2023-06-01 21:19:40.795 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.pressure" every 60 sec. (initial delay 26 sec.)
2023-06-01 21:19:40.797 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.adaptive_curve" every 60 sec. (initial delay 1 sec.)
2023-06-01 21:19:40.799 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.energy_sum_hwc" every 60 sec. (initial delay 8 sec.)
2023-06-01 21:19:40.802 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.maintenance_date" every 60 sec. (initial delay 2 sec.)
2023-06-01 21:19:40.804 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.energy_sum_this_month_hc" every 60 sec. (initial delay 11 sec.)
2023-06-01 21:19:40.806 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.energy_sum_this_month_hwc" every 60 sec. (initial delay 7 sec.)
2023-06-01 21:19:40.810 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.energy_sum_hc" every 60 sec. (initial delay 25 sec.)
2023-06-01 21:19:40.822 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.yield_total" every 60 sec. (initial delay 24 sec.)
2023-06-01 21:19:40.824 [INFO ] [ng.ebus.internal.handler.EBusHandler] - Register polling for "gen.energy_sum_last_month_hc" every 60 sec. (initial delay 6 sec.)
2023-06-01 21:19:41.885 [INFO ] [nternal.manager.ShellyManagerServlet] - Shelly Manager started at http(s)://192.168.1.50:8080/shelly/manager
2023-06-01 21:19:41.992 [INFO ] [rt.modbus.internal.ModbusManagerImpl] - Modbus manager activated
2023-06-01 21:19:42.829 [INFO ] [discovery.ShellyDiscoveryParticipant] - shellyuni-34945478c1b1: Device 192.168.1.51 reported Access defined (missing userid/password or incorrect).
2023-06-01 21:19:43.077 [ERROR] [org.openhab.core.items.GenericItem ] - Tried to set invalid state 0.0 (DecimalType) on item SerialBridge_BinaryData of type StringItem, ignoring it
2023-06-01 21:19:43.476 [INFO ] [.transport.mqtt.MqttBrokerConnection] - Starting MQTT broker connection to '192.168.1.50' with clientid 7c7d85a5-39aa-4f3b-bb92-b72913b979e5
2023-06-01 21:19:44.130 [ERROR] [org.openhab.core.items.GenericItem ] - Tried to set invalid state 0.0 (DecimalType) on item SerialBridge_StringData of type StringItem, ignoring it
2023-06-01 21:19:45.267 [INFO ] [y.internal.handler.ShellyBaseHandler] - shellyuni-34945478c1b1: Device is running a Beta version: /20210105-095645