Kodi on Ubuntu Studio filled disk, somewhere?

Apologies in advance if there is an existing answer I should consult... Fired up Kodi for the first time on my Ubuntu Studio 24.04 box. It has a 1 TB hard drive, of which almost half is consumed by the .flac files. Before running Kodi, about a quarter of the disc was free. I went through and added the appropriate media directories to to kodi's configuration, and initially it seemed to be working. Came back this morning, selected music, and rather than coming up with the list of albums Kodi locked up, unable to write log files to a full disk. Killing Kodi confirms disk is full, but it isn't clear what or where the additional space was consumed. /home, including the media, still reports under 500GB. Going through other directories under / with sudo du, I'm not finding anything over 12 GB (for /usr). So I'm very confused about where the space went. Admittedly ls | xargs sudo du -sh executed from / reports that it can't access things under /proc/117484 or /run/user/1000/doc. Has anyone else seen this, or does anyone have a suggestion for where to look for the missing gigabytes? (No, I haven't tried just rebooting yet; I'm a trifle afraid to do so before I know I have enough disk space to run safely. )