I've been looking at how to sync my two Macs. There are lots of options out there but none I'm comfortable with: DropBox. It appears that what people do is put their data files into the DropBox folder locally (or make symbolic links to that folder) and DropBox then monitors this folder locally, if changes are made it propogates the changes to their server and then out to other machines/devices under your account. I could be wrong and it monitors both local and server. Anyhow the trouble I have is that I've got tens of gigs and I don't see why I should ever have to take the bandwidth/time/security hit of using the Internet as the go-between. Plus I'm uncomfortable with DropBox acting as a blackbox; i.e. no idea the logic it's using to determine changes, determine conflicts or manage resolution. JungleDisk/BackBlaze with Chronosync. Using Chronosync means that you have full control and transparency, i.e. know logic and have logs. I was going to put aside my concerns of using cloud storage (bandwidth/accessibility/security), however JungleDisk just purged around 60 gig of my data because a 2USD invoice failed to process and I was completely unaware of the invoice processing failure. So for now, cloud storage is out. (if I do go to cloud, I'll try BackBlaze next time as JungleDisk clearly can't be trusted) Sync over LAN between two Macs (e.g. via Bonjour) and use Chronosync to perform the sync. Not a bad setup, but I've got the feeling that placing a third disk in between, is somehow cleaner and gives overall better protection. Therefore I've decided to keep two Macs in sync, to use Chronosync plus a NAS (in my case a QNAP 639-pro) as the middle man. Others must have done a similar setup (after all it's just a variation on using an external drive as the middle ground). So some preliminary questions are: do I need to be concerned that the NAS uses EXT3 (Linux) fielsystem; i.e. will ownership/group permissions or extended file attributes be an issue? Is there an issue with not syncing file metadata (.ds_store files comes to mind)? Syncs take a very long time when you've got tens of gigs, however often it's just a handful of files changing, i.e. OmniFocus, Devonthink, 1Password plus a few active project files. So it seems it's a good idea to have a full sync and some quick sync. Do people have a similar setup and can describe their Chronosync configs? It would appear the safest option is to close down 1password, OmniFocus etc. on one machine before hitting sync on that machine, but this introduces overhead, but I guess it depends on how the likes of 1Password writes to file and when Thoughts appreciated.