[CentOS] vsftpd log issues

Sat Dec 31 10:48:02 UTC 2011
Timo Neuvonen <timo-news at tee-en.net>

I have an up-to-date CentOS 6 with reasonable amount of ftp activity (a 
dozen of network cameras uploading images every second 24x7).

The first issue was that the whole /var filesystem was about to get full,
because of huge ftp daemon log.

vsftpd.conf says:

# You may override where the log file goes if you like. The default is shown
# below.
xferlog_file=/var/log/vsftpd.log

Ok, the above works now. But while the setting was (by default) commented
out, the default wasn't  /var/log/vsftpd.log  but  /var/log/xferlog  which
was growing without limits (it was over 6 GB when I first time noticed the
problem) since logrotate tried to rotate vsftpd.log

-rw-------  1 root root         0 Dec 31 03:07 vsftpd.log
-rw-------  1 root root  39134459 Dec 31 12:19 vsftpd.log.1
-rw-------  1 root root 433305200 Dec 30 22:03 xferlog

Now, after uncommenting the log file setting line in the conf the next issue
is, that logrotate does rotate the log files (the old one gets .1 postfix 
added to its name and a new file is created), but it still keeps writing to 
the original file (which is renamed now)

In the ls -l listing above:
- vsftpd started to write log vsftpd.log around 10pm last night (when I
uncommented the log setting from the conf and restarted the daemon, until
that it was logging to xferlog)
- during the night logrotate has changed the name of the existing log file
to ...log.1 but now, several hours later, this renamed old file is still
used for logging, and the new ...log file remains empty!

Is there some simple option in logrotate's conf that could change this
behaviour? Or how to fix this. There must be many others who already have
run into this issue.

Regards,
Timo