Clearing my thumbnail cache before a backup; I searched to see if there was a configuration point to limit the size of the cache as dolphin was freezing during the operation. I found this bug report https://bugs.kde.org/show_bug.cgi?id=79943
that has been running for a long, long time. It's certainly worth a read as it seems the bug can cause major headaches to people without a large amount of space.
Has anyone found a good safe way to regularly clean the cache? I'm tempted by the startup script mentioned at the end but I've never done such a thing and am a little nervous about it - especially as it's not written for Sabayon.