Varnish memory consumption issues?

[pub crawler]

Hello, new to Varnish.

We have been running Varnish for about 5 days now. So far, excellent product.

We have a potential issue and I haven't seen anything like this before.

We just restarted Varnish - we have a 1GB cache file on disk. When I
run top, I see Varnish is using :

10m RES
153g VIRT

Why is Varnish reporting this sort of VIRT memory?  How do we correct
that usage number or reset it?