Quoting Rod Rodolico (rodo@???):

> FWIW, I run several servers and I tried doing without swap a few years
> ago. I think it was Wheezy, but it may be even older. If memory serves
> me well, it was a couple of Xen DOM0's, and I was careful to allocate my
> DOMU's so that I had 8-12G of RAM just for the DOM0.
>
> I ended up with some erratic lockups on the servers, which I solved by
> throwing creating a small swap (on a RAID, but I never expect the
> machines to use swap). Since I've done that, I have had no other issues.
>
> I did not investigate any further; I just figured I hacked off the Unix
> gods by not having any swap. I'd advise testing like crazy before
> putting a machine into production without a swap.

Amen, brother. Words of wisdom.

I've been bearing in mind the possibility of outcomes like that during
acceptance testing, and thus would then adopt a fallback of adding a
swap file.

Swap files were common in Linux systems of the early '90s, but then fell
out of use because swap partitions has a perfomance advantage. But
then, someone found and fixed the performnce gap in the 2000s. Most
admins just don't remember the option exists.