Forever? Given you have enough RAM. I have never used a swap partition under Linux (in recent years anyway) and have always had the page file disabled under WinXP on my main system. Never had any problems with it.
Why would you need swap space on a file server?
If you run out of dram the OOM reaper will start killing off processes, so you'll get some very mysterious symptoms. The other point is that Linux and especially the X11 bits (not needed on a file server) have been growing larger over the years, so do use "free" and "ps" to examine how much memory is being used. You might be better off creating a swap on a spun-down disk than having no swap at all. If that's unacceptable, then you should rebuild your kernel to panic rather than reap processes. It's better for a server to fail than to act 'twitchy' at random times.
Personally if I was using flash for the root, I'd mount it read-only. You can always "mount -o remount,rw .." when you need to change configs. You'll need to create a r/w /var in a ram partition some logs, pidfiles & such are spooled there. Also examine the "noatime,nodiratime" mount options and the "commit=" options for any flash r/w.