How can I delete the cache in discourse?

[merefield (Robert)]

You can clear redis.

After upgrade, forum thinks it is mid-upgrade

Ah, I think it’s un-stuck now. I tried /var/discourse/launcher enter app redis-cli flushall which didn’t seem to work, so then I tried this and after a forced page refresh, it looks happy now. (Possibly I should have tried that forced page refresh after the first, simpler, form.)

But you may simply need a bigger disk :).