Hello, I have the latest install of NC on ubuntu with Mariadb. Pregeneration completed of thumbnails. Some images seemingly random, didn’t generate a preview. I went back to the config.php and added a line ‘preview_max_filesize_image’ => 500,
files:scan followed by preview:generate–all didn’t update the files with missing thumbs. OK…so then I opened nextcloud file explorer, searched for the file names, found them. They still don’t have a thumbnail, but they open up. Expectation was that the thumbnail would generate upon the search, but it did not.
What are some other possible solutions, I have already removed/added the pictures app, cleared cache (deleted the data folder and all contents/deleted all users and user data) rebuilt and rescanned and re indexed. Files still look the same. In windows, those files have a thumbnail, no corruption.
Any ideas? config.php was the only file I changed to allow these files to load. The file is actually only 30 mb in size and is in a batch of images of similar size , some of which load some don’t. Then I found some random non large images that also didn’t load, but in the same batch other images worked.
Is this a database issue where it has the wrong file to look for…or what.
preview_max_memory comes to mind as a possible culprit.[1]
There may be some other clues in your Nextcloud Server logs (particularly with loglevel0 temporarily set), though some preview generation errors aren’t logged under normal conditions because image processing is notoriously easy to trigger failures with (consider that in a large batch of images, particularly from a bunch of difference sources, chances are that some images will be corrupt or have non-compliant formats).
Also note that pre-generating previews may not be so important anymore, since concurrency support was added in… I think it was late in the NC26 cycle.[2]
What backend are you using for preview generation?[3]
I had the max image size already set, but it didn’t work. I tried a few other additional items. Here’s a copy of my config for those who have trouble in the future…
followed by a files:scan and generate:preview-all -vvv.
After these additional changes to /var/www/html/nextcloud/config/config.php both large thumbs and almost all broken thumbs worked. Setting to -1 made them load actually.