Bi-directional sync between HFS+ host fs and ext4 VM fs

Question

I'm developing for a Linux-based embedded system, where I have a build process from hell, at least to generate a full flashable binary -- tons of dependencies, proprietary compiler, etc. To make development setup easier for new developers, and uniform across our development team, I've adopted Vagrant. But, there's a snag...

So Vagrant spins up a VM and provisions it with our dependencies and tools. Then it mounts the source tree on the host within /vagrant on the VM. However, we cannot build within this directory -- mounts between the host and the VM do not support mmap (at least not in Virtualbox), which the build relies upon. With our developers that run OS X, things are even worse as their host OS is HFS+, case-insensitive out of the box -- the build requires a case-sensitive FS. So developers are forced to work within the VM, which is constraining if you're used to particular development tools in OS X say, and simply want to use the terminal for compilation.

Seems what's needed is a real-time (eg inotify based?) bi-directional sync mechanism that would keep /vagrant in sync with say /home/vagrant, which is not a mount point but simply part of the VM's ext4 fs, so produced/edited files and symlinks are synced. Is there such a mechanism? Closest thing I've found is aufs, but I'm not sure that does what we want.

Answer 1

我最终使用了NFS（包含在Vagrant和OS X中），并且已经运行了好几个月。