After downloading a whole bunch of stuff and filling up the file system, I got a panic:

w"/dev/sdC0/fscache" disk cache bucket 58 is full.

The system won't boot from that disk, but I can try to mount it from a live cd and debug, if someone can give me a hand with how to do it.

this sucks. you cannot resize the cache without destroying its contents loosing the changes. theres no good solution implemented yet so best is to avoid this situation.

what you can do in any case is ream the cache and revert to the last dump (recover main command in config mode) but then you'll loose the changes in the cache.

this is related to issue #64