FreeBSD doesn't overcommit the available memory (RAM + swap) by default.
Don't use swapfiles in FreeBSD because the file system write paths of UFS and ZFS potentially allocate memory. Both geom_mirror (software RAID-1) and geom_eli (disk encryption) are fine and I would recommend using GELI to create a onetime keys for mirrored swap partitions at boot.
An other good habit to get into is to limit the resources available to your services to some generous upper bound you expect them to require. The most flexible way to enforce those are restrictions in FreeBSD are hierarchical resource limits. Use them and monitor resource consumption. That way you get an early warning before a rouge process drives the system into massive swapping.
Don't use swapfiles in FreeBSD because the file system write paths of UFS and ZFS potentially allocate memory. Both geom_mirror (software RAID-1) and geom_eli (disk encryption) are fine and I would recommend using GELI to create a onetime keys for mirrored swap partitions at boot.
An other good habit to get into is to limit the resources available to your services to some generous upper bound you expect them to require. The most flexible way to enforce those are restrictions in FreeBSD are hierarchical resource limits. Use them and monitor resource consumption. That way you get an early warning before a rouge process drives the system into massive swapping.