rsync

It's been a well-known fact that using native VirtualBox or VMWare shared folders is a terrible idea if you're developing a Drupal site (or some other site that uses thousands of files in hundreds of folders). The most common recommendation is to switch to NFS for shared folders.

NFS shared folders are a decent solution, and using NFS does indeed speed up performance quite a bit (usually on the order of 20-50x for a file-heavy framework like Drupal!). However, it has it's downsides: it requires extra effort to get running on Windows, requires NFS support inside the VM (not all Vagrant base boxes provide support by default), and is not actually all that fast—in comparison to native filesystem performance.

I was developing a relatively large Drupal site lately, with over 200 modules enabled, meaning there were literally thousands of files and hundreds of directories that Drupal would end up scanning/including on every page request. For some reason, even simple pages like admin forms would take 2+ seconds to load, and digging into the situation with XHProf, I found a likely culprit:

I've often had trouble copying files with Mac OS X's Finder. From back in the Mac OS X Beta days (when it was based on NeXT's UI), hard drive to hard drive copies, network copies, and backups have often had strange quirks, and one of the strangest I've yet found happened yesterday when I tried copying a ~170GB Aperture library from one external USB drive to another.

I tried copying the library three times, and each time the copy would get to about 24GB, the hard drive (from which the library was being copied) would make a loud CLICK, and then it would unmount and remount, stopping the library file copy. This particular drive has never had troubles in the past, and the fact that it kept doing the CLICK-die thing at 24GB meant that there may have been a file problem or a Finder bug causing the problem.