I think I had the same issue. Rolled back a day with dietpi-backup. dietpi-backup is a must to have setup for your NAS!
Oct 26 16:13:35 DietPi systemd\[1\]: Started jellyfin.service - Jellyfin Media Server.
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Setting cache path: /mnt/dietpi_userdata/jellyfin/cache
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Kestrel is listening on 0.0.0.0
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Jellyfin version: 10.11.0
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Environment Variables: \[“\[JELLYFIN_ADDITIONAL_OPTS, \]”, “\[JELLYFIN_USER, jellyfin\]”, “\[JELLYFIN_LOG_DIR, /var/log/jellyfin\]”, “\[JELLYFIN_WEB_OPT, --webdir=/usr/share/jellyfin/web\]”, “\[JELLYFIN_CONFIG_DIR, /etc/jellyfin\]”, “\[JELLYFIN_ARGS, $JELLYFIN_WEB_OPT $JELLYFIN_FFMPEG_OPT $JELLYFIN_SERVICE_OPT $JELLYFIN_NOWEBAPP_OPT $JELLFIN_ADDITIONAL_OPTS --datadir $JELLYFIN_DATA_DIR --configdir $JELLYFIN_CONFIG_DIR --logdir $JELLYFIN_LOG_DIR --cachedir $JELLYFIN_CACHE_DIR\]”, “\[JELLYFIN_FFMPEG_OPT, --ffmpeg=/usr/lib/jellyfin-ffmpeg/ffmpeg\]”, “\[JELLYFIN_DATA_DIR, /mnt/dietpi_userdata/jellyfin\]”, “\[JELLYFIN_CACHE_DIR, /mnt/dietpi_userdata/jellyfin/cache\]”\]
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Arguments: \[“/usr/lib/jellyfin/bin/jellyfin.dll”, “–webdir=/usr/share/jellyfin/web”, “–ffmpeg=/usr/lib/jellyfin-ffmpeg/ffmpeg”\]
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Operating system: Debian GNU/Linux 12 (bookworm)
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Architecture: X64
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] 64-Bit Process: True
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] User Interactive: True
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Processor count: 4
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Program data path: /mnt/dietpi_userdata/jellyfin
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Log directory path: /var/log/jellyfin
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Config directory path: /etc/jellyfin
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Cache path: /mnt/dietpi_userdata/jellyfin/cache
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Temp directory path: /tmp/jellyfin
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Web resources path: /usr/share/jellyfin/web
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Application directory: /usr/lib/jellyfin/bin/
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[INF\] Storage path `/mnt/dietpi_userdata/jellyfin/data` (Fixed) successfully checked with 210.8GB free which is over the minimum of 2GB.
Oct 26 16:13:36 DietPi jellyfin\[1667\]: \[16:13:36\] \[FTL\] Unhandled Exception
Oct 26 16:13:36 DietPi jellyfin\[1667\]: System.InvalidOperationException: The path `/var/log/jellyfin` has insufficient free space. Required: at least 512MB.
Oct 26 16:13:36 DietPi jellyfin\[1667\]: at Jellyfin.Server.Implementations.StorageHelpers.StorageHelper.TestDataDirectorySize(String path, ILogger logger, Int64 threshold)
Oct 26 16:13:36 DietPi jellyfin\[1667\]: at Jellyfin.Server.Implementations.StorageHelpers.StorageHelper.TestCommonPathsForStorageCapacity(IApplicationPaths applicationPaths, ILogger logger)
Oct 26 16:13:36 DietPi jellyfin\[1667\]: at Jellyfin.Server.Program.StartApp(StartupOptions options)
Oct 26 16:13:36 DietPi jellyfin\[1667\]: at Jellyfin.Server.Program.(String[ ] args)
Oct 26 16:13:36 DietPi jellyfin\[1667\]: Unhandled exception. System.InvalidOperationException: The path `/var/log/jellyfin` has insufficient free space. Required: at least 512MB.
Oct 26 16:13:36 DietPi jellyfin\[1667\]: at Jellyfin.Server.Implementations.StorageHelpers.StorageHelper.TestDataDirectorySize(String path, ILogger logger, Int64 threshold)
Oct 26 16:13:36 DietPi jellyfin\[1667\]: at Jellyfin.Server.Implementations.StorageHelpers.StorageHelper.TestCommonPathsForStorageCapacity(IApplicationPaths applicationPaths, ILogger logger)
Oct 26 16:13:36 DietPi jellyfin\[1667\]: at Jellyfin.Server.Program.StartApp(StartupOptions options)
Oct 26 16:13:36 DietPi jellyfin\[1667\]: at Jellyfin.Server.Program.(String[ ] args)
Oct 26 16:13:36 DietPi systemd\[1\]: jellyfin.service: Main process exited, code=killed, status=6/ABRT
Oct 26 16:13:36 DietPi systemd\[1\]: jellyfin.service: Failed with result ‘signal’.
Oct 26 16:13:36 DietPi systemd\[1\]: jellyfin.service: Scheduled restart job, restart counter is at 4.
Oct 26 16:13:36 DietPi systemd\[1\]: Stopped jellyfin.service - Jellyfin Media Server.
Oct 26 16:13:36 DietPi systemd\[1\]: Started jellyfin.service - Jellyfin Media Server.
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Setting cache path: /mnt/dietpi_userdata/jellyfin/cache
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Kestrel is listening on 0.0.0.0
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Jellyfin version: 10.11.0
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Environment Variables: \[“\[JELLYFIN_ARGS, $JELLYFIN_WEB_OPT $JELLYFIN_FFMPEG_OPT $JELLYFIN_SERVICE_OPT $JELLYFIN_NOWEBAPP_OPT $JELLFIN_ADDITIONAL_OPTS --datadir $JELLYFIN_DATA_DIR --configdir $JELLYFIN_CONFIG_DIR --logdir $JELLYFIN_LOG_DIR --cachedir $JELLYFIN_CACHE_DIR\]”, “\[JELLYFIN_DATA_DIR, /mnt/dietpi_userdata/jellyfin\]”, “\[JELLYFIN_CONFIG_DIR, /etc/jellyfin\]”, “\[JELLYFIN_CACHE_DIR, /mnt/dietpi_userdata/jellyfin/cache\]”, “\[JELLYFIN_FFMPEG_OPT, --ffmpeg=/usr/lib/jellyfin-ffmpeg/ffmpeg\]”, “\[JELLYFIN_LOG_DIR, /var/log/jellyfin\]”, “\[JELLYFIN_WEB_OPT, --webdir=/usr/share/jellyfin/web\]”, “\[JELLYFIN_USER, jellyfin\]”, “\[JELLYFIN_ADDITIONAL_OPTS, \]”\]
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Arguments: \[“/usr/lib/jellyfin/bin/jellyfin.dll”, “–webdir=/usr/share/jellyfin/web”, “–ffmpeg=/usr/lib/jellyfin-ffmpeg/ffmpeg”\]
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Operating system: Debian GNU/Linux 12 (bookworm)
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Architecture: X64
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] 64-Bit Process: True
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] User Interactive: True
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Processor count: 4
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Program data path: /mnt/dietpi_userdata/jellyfin
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Log directory path: /var/log/jellyfin
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Config directory path: /etc/jellyfin
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Cache path: /mnt/dietpi_userdata/jellyfin/cache
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Temp directory path: /tmp/jellyfin
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Web resources path: /usr/share/jellyfin/web
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Application directory: /usr/lib/jellyfin/bin/
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[INF\] Storage path `/mnt/dietpi_userdata/jellyfin/data` (Fixed) successfully checked with 210.8GB free which is over the minimum of 2GB.
Oct 26 16:13:37 DietPi jellyfin\[1683\]: \[16:13:37\] \[FTL\] Unhandled Exception
Oct 26 16:13:37 DietPi jellyfin\[1683\]: System.InvalidOperationException: The path `/var/log/jellyfin` has insufficient free space. Required: at least 512MB.
Oct 26 16:13:37 DietPi jellyfin\[1683\]: at Jellyfin.Server.Implementations.StorageHelpers.StorageHelper.TestDataDirectorySize(String path, ILogger logger, Int64 threshold)
Oct 26 16:13:37 DietPi jellyfin\[1683\]: at Jellyfin.Server.Implementations.StorageHelpers.StorageHelper.TestCommonPathsForStorageCapacity(IApplicationPaths applicationPaths, ILogger logger)
Oct 26 16:13:37 DietPi jellyfin\[1683\]: at Jellyfin.Server.Program.StartApp(StartupOptions options)
Oct 26 16:13:37 DietPi jellyfin\[1683\]: at Jellyfin.Server.Program.(String[ ] args)
Oct 26 16:13:37 DietPi jellyfin\[1683\]: Unhandled exception. System.InvalidOperationException: The path `/var/log/jellyfin` has insufficient free space. Required: at least 512MB.
Oct 26 16:13:37 DietPi jellyfin\[1683\]: at Jellyfin.Server.Implementations.StorageHelpers.StorageHelper.TestDataDirectorySize(String path, ILogger logger, Int64 threshold)
Oct 26 16:13:37 DietPi jellyfin\[1683\]: at Jellyfin.Server.Implementations.StorageHelpers.StorageHelper.TestCommonPathsForStorageCapacity(IApplicationPaths applicationPaths, ILogger logger)
Oct 26 16:13:37 DietPi jellyfin\[1683\]: at Jellyfin.Server.Program.StartApp(StartupOptions options)
Oct 26 16:13:37 DietPi jellyfin\[1683\]: at Jellyfin.Server.Program.(String[ ] args)
Oct 26 16:13:37 DietPi systemd\[1\]: jellyfin.service: Main process exited, code=killed, status=6/ABRT
Oct 26 16:13:37 DietPi systemd\[1\]: jellyfin.service: Failed with result ‘signal’.
Oct 26 16:13:37 DietPi systemd\[1\]: jellyfin.service: Scheduled restart job, restart counter is at 5.
Oct 26 16:13:37 DietPi systemd\[1\]: Stopped jellyfin.service - Jellyfin Media Server.
Oct 26 16:13:37 DietPi systemd\[1\]: jellyfin.service: Start request repeated too quickly.
Oct 26 16:13:37 DietPi systemd\[1\]: jellyfin.service: Failed with result ‘signal’.
Oct 26 16:13:37 DietPi systemd\[1\]: Failed to start jellyfin.service - Jellyfin Media Server.