Symantec AV Corporate takes 7 hours to back up 174000 file..

I have a new client who runs Symantec AV Corporate. It scans every
night starting at 4am but its almost 11:35 and it just finished. 7
hours plus to do 174000 files is way to long. It scans both the machine
its installed on and a network file server which is where most of the
files it scans reside. Trying to figure out why it takes so long. The
only thing I am thinking is that the file server, which is also
responsible for the backups using Arcserv is a dogass slow machine. It
is slow as molasses to use. It does not seem to have speed issues just
running its backup routines or serving up the files to users. Just
don't try to launch any programs on it or anything. Ya need to take a
vacation and come back when the window finally appears Smile. I will be
replacing that server with Snapserver 1100 in the coming weeks to
handle all the file serving duties and eventually retire the older
server and assign the backup duties to their much newer and faster
Exchange server. Now I don't want the virus scan running during the
morning working hours like it is now but I also don't want it have to
schedule it to start earlier as I have a few different backup jobs
scheduled between 8pm and 2am and don't want the viruscheck running
during that time either, especially since the file server aka Speedy
Gonzalez has to handle the backup routines as well. Would probably slow
things down even more. But it seems to me it should take alot less time
to scan even if it is scanning a network drive located on a slow
machine. Any ideas or suggestions guys?

Adam