When an AppleShare server is started up, it initiates a two-pass process
that ensures that the PDS (Parallel Directory Structure) is valid. During
the first pass, it makes sure that for every entry in the PDS, there is a
corresponding entry in the catalog. On the second pass, it does the
opposite. A server with a very large number of files can takes an hour
or more to verify.
If this interval is unacceptable, turn off the server less often. To blank
the screen when you don't need to see it, turn down the screen intensity
or install a desk accessory that blanks the screen automatically after a
period of inactivity.