Enormous space consumption due to thumbnails – how can I get rid of them?

[SottoVoce]

Hi there,

after running an OwnCloud installation for some years where we also share images (photos) with ~90 users, I just noticed that we have a huge amount of thumbnails on our web space, taking up enormous space. It seems that thumbnails get created in different sizes and separately for every user (why is that?). For some users, those thumbnails take up several hundred megabytes. In total it’s several gigabytes. This means that the thumbnails take up by far the most space on our web space.

I already set the preview_max_x and preview_max_y variables in config.php to 256. It seems that OwnCloud now creates new thumbnails of that size, but the old thumbnails are still there. How can I get rid of them? I already tried occ files:cleanup and occ files:scan, but neither helps.

Is there a way to configure OwnCloud so that thumbnails only exist once, not separately for every user? After all, they are identical for all users!?

The OwnCloud version is 10.9.1 (should be up-to-date).

Thanks and best regards,
Oliver

[alfredb]

AFAIK you can simply delete those thumbnail files.

[SottoVoce]

Thanks for the tip! But this hardly sounds like an “officially recommended solution” to me. I’ve read that after physically deleting them, the files will still be referenced in some database (or some cache?). Won’t that cause problems?

[alfredb]

@SottoVoce

Won’t that cause problems?

No. They will just be recreated upon request. The meanest thing that can happen is that ownCloud displays a default thumbnail until the suitable file is recreated.