Lost thousands of listings during server downtime

My site's server went down for 2 days this week, on the 28th and 29th
and now all my Google listings are gone. I had several thousand
listings for last few years that now have vanished. So I'm wondering
if Google will re-spider all my previously listed pages directly. Or
will they start from scratch and try to find as many pages on my site
as they can.

The reason I ask is because many of these listed pages were on my
members' sites, which are subdomain addresses on my domain. They would
have been submitted manually to Google and I have no direct link to
them off my main site for their spiders to find.
Thanks in advance.
Hibes