Post Sun Sep 12, 2021 12:18 pm

Could not lock/flush user prefs messages

I just installed vanilla Debian Bullseye arm64 on a Raspberry Pi 4, then ffmpeg x264 dcraw openjdk 11 and Serviio 2.1. Serviio appears to be running ok - it's presently indexing my media library, and I can play videos already added, but when i run 'sudo systemctl status serviio.service' at the console, I see the following:
  Code:
nick@serviio:~$ sudo systemctl status serviio.service
● serviio.service - Serviio media Server
     Loaded: loaded (/etc/systemd/system/serviio.service; enabled; vendor preset: enabled)
     Active: active (running) since Sun 2021-09-12 21:45:32 AEST; 9min ago
   Main PID: 473 (java)
      Tasks: 145 (limit: 9242)
     Memory: 909.2M
        CPU: 11min 42.655s
     CGroup: /system.slice/serviio.service
             ├─ 473 java --add-modules jdk.unsupported -Xmx512M -Xms20M -XX:+UseG1GC -XX:GCTimeRatio=1 -XX:MinHeapFreeRatio=10 -XX:>
             └─4197 ffmpeg -i /mnt/library/Videos/Snooker/Masters2020/Extra-Day_2.mkv

Sep 12 21:52:19 serviio serviio.sh[473]: Could not lock User prefs.  Unix error code 2.
Sep 12 21:52:19 serviio serviio.sh[473]: Couldn't flush user prefs: java.util.prefs.BackingStoreException: Couldn't get file lock.
Sep 12 21:52:49 serviio serviio.sh[473]: Could not lock User prefs.  Unix error code 2.
Sep 12 21:52:49 serviio serviio.sh[473]: Couldn't flush user prefs: java.util.prefs.BackingStoreException: Couldn't get file lock.
Sep 12 21:53:19 serviio serviio.sh[473]: Could not lock User prefs.  Unix error code 2.
Sep 12 21:53:19 serviio serviio.sh[473]: Couldn't flush user prefs: java.util.prefs.BackingStoreException: Couldn't get file lock.
Sep 12 21:53:49 serviio serviio.sh[473]: Could not lock User prefs.  Unix error code 2.
Sep 12 21:53:49 serviio serviio.sh[473]: Couldn't flush user prefs: java.util.prefs.BackingStoreException: Couldn't get file lock.
Sep 12 21:54:19 serviio serviio.sh[473]: Could not lock User prefs.  Unix error code 2.
Sep 12 21:54:19 serviio serviio.sh[473]: Couldn't flush user prefs: java.util.prefs.BackingStoreException: Couldn't get file lock.
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The messages are happening at 90 second intervals. What causes the 'Could not lock User prefs' and 'Couldn't flush user prefs' messages? Should I just ignore them? The serviio user is the owner of the serviio install dir and everything in it:
  Code:
nick@serviio:~$ ls -l /opt/serviio-2.1/
total 108
drwxr-xr-x 2 serviio serviio  4096 Sep 12 21:39 bin
drwxr-xr-x 2 serviio serviio  4096 May  3  2020 config
drwxr-xr-x 2 serviio serviio  4096 Sep 12 21:39 legal
drwxr-xr-x 2 serviio serviio  4096 Sep 12 21:39 lib
drwxrwxrwx 6 serviio serviio  4096 Sep 12 21:43 library
-rw-r--r-- 1 serviio serviio  3595 May  3  2020 LICENCE.txt
drwxr-xr-x 2 serviio serviio  4096 Sep 12 21:43 log
-rw-r--r-- 1 serviio serviio 10900 May  3  2020 NOTICE.txt
drwxrwxrwx 2 serviio serviio  4096 May  3  2020 plugins
-rw-r--r-- 1 serviio serviio  4636 May  3  2020 README.txt
-rw-r--r-- 1 serviio serviio 56845 May  3  2020 RELEASE_NOTES.txt