(Warning for the geek-averse: the following post will, undoubtedly, bore you to death.)

This weekend, in an effort to better handle the ever-increasing tide of spam that’s been flowing into all the inboxes I host on my mailserver, I set up a second Linux box to do all the mail filtering. (SpamAssassin has a pretty snazzy mechanism that lets you offload the spam checking work onto a different machine as the mail server.) After getting the client/server stuff up and running, I figured out that there were a few users that would end up using the spam stuff on both machines (the mail server and the filtering server); this meant that each user would end up with two entirely different SpamAssassin preference files, as well as two different Bayes databases. And this all led to figuring out how to set up NFS shares, working through each machine’s firewall, so that this could be avoided. Fun fun fun.

Here are some pages that I found particularly useful in this grand endeavor:

  • The Linux NFS How-To, which (like most of the how-tos) is a simple step-by-step walk through setting up both sides of an NFS connection.
  • Some information about autofs, which has the potential to make life a lot easier.
  • Configuring NFS under Linux for Firewall control, which goes through all the changes that have to be made to various configuration files in order to get NFS to behave in a firewall-friendly way. (It doesn’t speak to how to get RedHat 7.2 to use a version of rpc.lockd that is willing to bind to a predefined port; that’s an exercise for another day.)
  • iptables options, which is one of the best translators of the gobbledygook that’s part and parcel of Linux firewall configuration.
  • FileThingie, a one-script PHP installation that lets users edit text files via the web. I’m using this to let one of my friends make changes to a few of his preferences files (including his SpamAssasin configuration).

It’s a cool setup, and it’s working beautifully.