I am running a Novell SBS 6.0 Sp4 server with the following loaded on it:
Arcserve 7.0
GroupWise Web Access 6.0 Sp4
Tobit Faxware 6.6 Sp5a
Sophos SAVI
Novell FTP

Everything had been running great for a year or so and suddenly about a
month a go the server started hanging about 3 - 3:30 am every night. I
know this from the other servers console logs. When it hangs nothing is
written to log files as far as I have found. I have moved the tape backup
to run in the afternoon and it locks up as well now. So I shutdown tape
backup and the server still locks up around 3 - 3:30 am. I have been
trying all sorts of stuff to figure out what has caused this and I have
just about pulled all my hair out. As far as I know I did nothing to
this server before this all came about.

Where do I begin to figure this out? I don't know what could be active
at 3:00 am, our office closes at 5:00 pm.