The default index is specified by a registry entry and it initially contains all virtual directories with "index this directory" and "read" attributes set. non-readable or non-virtual directories must be added in the directory folder of the Index Server control panel.
From my Server Failures log: All last week I've been having horrible problems with the server getting overloaded. % Processor Usage goes to 100% and stays. Web site response is more and more sluggish and the number of users connected climbs to insane levels. The TaskList shows that inetinfo or mtx is takeing 99% of the available cycles. Useing Performance Monitor to watch the threads of those processes shows that different threads are maxing out at different times.
Running windbg, attaching the process and viewing a stack dump for the maxed out threads always shows that MSVCRT.DLL is running. No info in MSKB related to that DLL other than that it is the Visual C runtime library. I don't run any Visual C code. Tried shutting off all CGI-BIN exe's. Upgradeing that DLL, etc... has no effect. Stopping the site or the entire web service has no effect (!).
And then... We notice that stopping the content index service frees up
the processor and disconnects most of the connected users. No content
index corrupt messages... server ran fine for an entire day with the search
functions disabled. Rebuilding the content index had no effect. I've disabled
the search functions (but kept the index server running) and the processor
never makes it above 5%! And I've served more pages than ever! Doing
one or two searches at a time (locally) sends the processor up to about 80
or 90% for the duration of the search. Doing 10 searches at once pegs the
meter and it never recovers.
So... the secret is: Don't run a busy NT web server with more than a Gig
of text in the search engine unless you throttle its use. I'm frantically
searching for a way to do that. For now, it just records the starting time
of each search and will not allow another one for a number of seconds after
that.