The size of the binary journal files and log file as parsed by "journalctl" differ greatly

Issue

• There is a difference in the size of the the below files (after persistent logging is enabled following article 696893):

# ls -alsh /var/log/journal/ff62cd3863554847a2414b981cfba22e/system.journal 
8.1M -rw-r-----+ 1 root systemd-journal 8.0M Apr 19 11:44 /var/log/journal/ff62cd3863554847a2414b981cfba22e/system.journal

# journalctl -all --no-tail --no-pager > /tmp/logs.txt
# du -sch /tmp/logs.txt
320K    /tmp/logs.txt
320K    total