
Overlayfs is quite a bit faster, e.g. with it the KDE 5 test takes ~7m instead of ~30m on my laptop (which is still not great, since plain 9pfs is ~4m30s).
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.