The port security/i2pd installs a configuration file for newsyslog to rotate /var/log/i2pd/i2pd.log and compress old copy and then send signal 1 to i2pd. i2pd ignores the signal and does not close/reopen the log so newly created by the newsysod i2pd.log remains unused and i2pd continues writing to now unlinked old file filling /var indefinitely.
Confirmed
A commit references this bug: Author: amdmi3 Date: Tue Aug 28 15:37:39 UTC 2018 New revision: 478322 URL: https://svnweb.freebsd.org/changeset/ports/478322 Log: - Fix log rotation by using right signal to make i2pd reopen its logfile PR: 230714 Reported by: eugen Changes: head/security/i2pd/Makefile head/security/i2pd/files/i2pd.newsyslog.conf.in