OpenVZ: VSwap configuration
OpenVZ has a much simplified memory configuration called VSwap, at least in current kernels: https://wiki.openvz.org/VSwap
It requires setting only 2 parameters, ram and swap, much easier than User beancounters.
I tried setting just the physpages and swappages in an ispconfig vm template and it errors that all the other parameters need to be specified.
Supporting VSwap seems to be as easy as making those other parameters optional in both the front end and in the .conf file that is generated, and maybe a bit of reorganizing the Advanced tab to put physpages and swappages together (at the top?) with a note that you only need to set those for VSwap config, and all others are optional. Could add a vm_overcommit setting there, too.
The Advanced tab under VM Servers already hides all of the individual User beancounters, it probably should also have a setting to adjust those two.