Hi there, @yotg,
Creating multiple thumbnail sizes increases disk usage, but the increase you see appears excessive. Here are a few steps you can take to figure that out:
1. **Thumbnail Sizes**: Check your theme and plugins to see if there are any unnecessary additional image sizes being created. Under Settings > Media, you can manage the default WordPress thumbnail sizes. Additionally, themes and plugins can add their own image sizes. You can check this under Appearance > Customize > Thumbnail Sizes. If any are not required, you can either reduce its dimensions if possible, or stop its generation altogether.
2. **Thumbnail Cleanup**: You could use a plugin to delete any unused or unnecessary thumbnails. Plugins like ‘Media Cleaner’ can help manage and clean up your media library.
3. **Image Optimization**: try using an image optimization plugin to reduce image file sizes without losing quality.
4. **Backup Excluded**: you can try excluding the thumbnail images from your backups. Usually, these can be re-generated using the original images if necessary, so there’s no need to include them in backups.
Can you please try these suggestions and let me know how it goes?
