"Tail -f" on symlink that points to a file on another drive has interval stops, but not when tailing the original file

I'm encountering a strange behaviour with tail -f, when tailing a symlink on an Ubuntu machine. Apparently, tail uses the default update interval of 1 second. If tailing the original file, it seems to update immediately. lrwxrwxrwx 1 root root 49 Sep 9 20:28 firewall_log-01.log -> /var/data/log/firewall_log-01.log Doing $ tail -f firewall_log-01.log "pauses" every second (roughly, haven't measured exactly), which fits the defaults for tail: -s, --sleep-interval=N with -f, sleep for approximately N seconds (default 1.0) When doing $ tail -f /var/data/log/firewall_log-01.log the output gets updated immediately, apparently not concerned with the default setting for interval. When I run tail -s 0.01: $ tail -f -s 0.01 firewall_log-01.log I basically have what I need, but I'm still confused by why this even happens. I can do a workaround by adding an alias to ~/.bashrc, but this seems like a kind of dirty workaround. Is there any logical reason for tail to behave like this?