A little less than 25 years ago, my then-new day job wanted me to build them a new mail server, using Linux.

I'd put together one or two public-facing mail servers before, but it'd been a few years and the landscape had changed (postfix was the new hotness, sendmail was old news, etc). And I had a FreeBSD machine at home that I'd previously built from garbage that I was using for NAT and a few other things.

So, wanting to appear all slick and stuff at the new job, I built a prototype at home on that FreeBSD box using a freebie dyndns subdomain (which was still practical at that time).

It all worked great. For a couple of years I even used it to host my own email at home. It was less trouble to maintain than the Linux-based thing I'd built at work even though they both started with the same software configs.

But that FreeBSD box was only ever a little forgettable trash-built machine, so there were no backups at all when the hard drive crashed completely (there were grooves worn into the platters) while I was out of town.

Which might normally be the end of the story, but: FreeBSD kept rolling just fine. Whatever data was in RAM (which apparently included at least sshd and bash) remained in RAM and stayed usable, and it kept routing packets like nothing had ever happened at all.

I marveled at this for a few weeks as this very broken machine kept flawlessly doing its NAT duties and providing solid Internet access for my LAN until I scrounged up enough pennies to buy my first "home router": A Linksys WRT54GS. (That little hackable Linux box was a very fun introduction to the rabbit hole of using hardware in unintended ways, but that's a story for a different comment section.)