Blew away .../var/varnish/HOSTNAME/ -- broke varnishstat, how to recover?

[Chris Shenton]

We're using varnish for a public site, works beautifully and handled  
getting slashdotted gracefully -- many thanks!

We built it with "zc.buildout" which creates .../parts/varnish/install/ 
var/varnish/FQDN/... and others.  In a recent update, I accidentally  
blew away the .../var/varnish/FQDN directory which contained a few  
files that seem necessary for "varnishstat" and perhaps others to work.

  bin.XXkP5ZYv
  _.c
  _.vsl

$ varnishstat
Cannot open /usr/local/mastersite_buildout/parts/varnish/install/var/ 
varnish/FQDN/_.vsl: No such file or directory

Varnish continues to serve well, so I haven't restarted.

What's the recommended way to re-create this directory?  I'm assuming  
restarting Varnish will re-create it but want to be sure.

We have to fill out pounds of paperwork in order to take any outage on  
a public server, no matter how small.  Is there a way to restart  
Varnish without any downtime -- to continue accepting but holding  
connections until restarted, rather like Apache's "apachectl graceful"  
does?  Other ideas?

Thanks.