What's your idea of a low-memory virtual machine? For test purposes I'm running FreeBSD/amd64 under Hyper-V in 128-MB RAM without any problems, although it is using around 32-MB of encrypted swap. That includes the Salt minion, Postfix, and an untuned static Apache 2.4 installation. Of course, it's much more comfortable in 256-MB RAM with around 44-MB RAM free according to top, and of course that's workload-dependent (e.g., my mail relay running amavisd-new and ClamAV wants 1.5-GB RAM after loading all of the spam and virus signatures). I could definitely see wanting to run FreeBSD in 128-MB or less RAM, but I'm very curious about your specific workloads. (It's the gearhead equivalent of wanting to look under the other guy's hood. If you're doing something cool, I want to hear about it!)
P.S. Hyper-V will let me go as low as 32-MB RAM, so thanks to you I'm keen to try out different operating system installs (and workloads) in low-memory environments.
P.P.S. Upvoted parent - I think the parent comment contributes to the discussion, even though I would personally love to see commenter go into more detail.
I used to run a typical apache/mysql/php/perl stack on amd64 image on 512 MB VM. Actually, I run many things in very tight memory environments on FreeBSD, there is always significantly more room on i386 (in comparison to amd64).
P.S. Hyper-V will let me go as low as 32-MB RAM, so thanks to you I'm keen to try out different operating system installs (and workloads) in low-memory environments.
P.P.S. Upvoted parent - I think the parent comment contributes to the discussion, even though I would personally love to see commenter go into more detail.