If it's only at 19% then why do you need more space? You've still got 81% left. To clear up space, delete stuff or move it to root /. Remove all the logs in /var/log while you're at, that's probably eating up a bunch of space. No real need to run e2fsck on /var since the tivo does it on it's own each time it reboots.
But the real ? remains, why is 81% free not enough?
But the real ? remains, why is 81% free not enough?