Thanks Vincent,
Yes, I tried following both
http://www.xwiki.org/xwiki/bin/view/AdminGuide/Virtualization
and
http://www.xwiki.org/xwiki/bin/view/FAQ/HowToSetupVirtualWikis
word-for-word.
It seems to be close to working. If I have XWiki.XWikiServerDomain1 with server www.domain1.com and XWiki.XWikiServerDomain2 with server set to www.domain 2.com, and I hit
http://www.domain1.com:8080/xwiki/bin/view/Main/WebHome
and
http://www.domain2.com:8080/xwiki/bin/view/Main/WebHome
it at least realizes there should be sites at both (ie it find a wiki), it's just using the same database for each. Do I need to do something to tell it to configure separate databases?
[And, if I change the server on domain2 from www.domain2.com to just domain2.com and hit http://domain2.com:8080/xwiki/bin/view/Main/WebHome with my browser, it says there's No Wiki at that address...]
Thanks!