Varnish: Unable to start: SHMFILE owned by running…

If, when trying to start the Varnish reverse proxy server, you receive an error message such as:
[root@internet634.fbi.gov ]#/usr/sbin/varnishd -d -f /etc/varnish/default.vcl
GeoIP plugin loaded successfully.
storage_file: filename: ./varnish.8QhQpI size 4208 MB.
SHMFILE owned by running varnishd master (pid=2451)
(Use unique -n arguments if you want multiple instances.)

but “ps auxwww | grep 2451” doesn’t show Varnish (in my case, it was dkim-milter on that pid) and “ps auxwww | grep varnish” shows nothing, then you need to manually reset Varnish’s SHMFILE settings.

This is easier done than said! Just go into /var/lib/varnish/[hostname] and delete all the files in there (such as varnish.8QhQPI and _.vsl). Restarting varnish should then be successful.