How to auto-wirelessly back up one mac to another?

February 24, 2010 5:40 PM

I have two newish macbook pro laptops (with OS X 10.6) and want one to automatically and wirelessly back-up to the other one so will always have a "hot backup" on the second machine (I inherited the second one, so seems a reasonable use). FWIW, I have DSL with wireless modem in the house, so wouldn't want the ability for the machines to talk with each other to allow inadvertant access from anyone from the web. How to set it up?
posted by tedthedog to computers & internet (8 answers total)

I'm not sure how to do what you want, but I thought I'd point out Time Capsule which is the usual solution for Mac wireless backup.
posted by whiskeyspider at 6:25 PM on February 24, 2010

Presuming you don't want to spring for OSX Server for both machines, this article shows how to create a time-machine-eque system using rsync (which will already exist in your 10.6 installs). The scripts provided will require a little modification, but not a great deal.
posted by pompomtom at 6:39 PM on February 24, 2010

PogoPlug might do what you want, with the added benefit (if you see it that way) of being able to access your files from pretty much anywhere but without putting them on the "cloud." Reviewed here yesterday coincidentally.
posted by webhund at 6:39 PM on February 24, 2010

Believe it or not, Windows Live Sync (free, Google it) works good for this now that the Snow Leopard update is available. I keep a macbook, a vista notebook/media server, a vista desktop computer, and an xp server all synchronized in near real-time, wirelessly, using Live Sync. Even works outside my firewall using secure tunnelling. I can work on my crap on any of these machines and it gets shoved over to the others within a minute or two. (I use time-machine for daily backups, and do offsite weeklies with SyncToy's "publish" mode.)

The gotcha: You can only sync 10,000 files maximum per "share" although you can have multiple shares. I use three, one for code projects, one for documentaton, and one active photography projects.

I do not sync operating system files, because that's silly. Just my own stuff.
posted by seanmpuckett at 7:11 PM on February 24, 2010

Mobile Me offers a similar service, although it's $99 / Year - they offer 20 GB of storage online, and will sync files, contacts, etc. between any computers - Mac or PC - that are logged in. Also, there's the web client, and iPhone, of course.

You may be able to sign up for a Mobile Me trial and see if you like it, and if you are willing to pay for it.
posted by GJSchaller at 7:20 PM on February 24, 2010

Thanks much for suggestions so far. But it wasn't the backup part that I'm most unsure about, it's really the "systems" part. That is, how to get the two laptops to talk with each other, and only each other, over a local wireless network so that if one laptop stays at home ( call it the hot backup machine), and the second laptop walks in the door, then the second laptop automatically sees the hot back up machine (at which point the backup software can do its thing over the local wireless network).
posted by tedthedog at 7:25 PM on February 24, 2010

Not sure if there's a more Mac friendly way to do this using rendezvous to detect presence, but the older way to do this would be something like:

Have your network is set up so each machine keeps it's IP (Set on the routers DHCP server).
Have a shell script that runs from cron as often as you like on the back up machine which basically does something like:
Ping the master - if there's no reply, do nothing, but if the machine responds
run rsync -ave 'ssh -i /path/to/your/key' user@masters_IP:/Users/you/ /Users/you/

You'd need to allow ssh access on the master machine with a key for authentication, and copy the public key to the backup machine. Google will help with the specifics of ssh-keys, ssh-agent and esoteric rsync options, but that's a good start.
posted by dirm at 8:32 PM on February 24, 2010

I can get my teeth into that, thanks dirm.
posted by tedthedog at 11:04 AM on February 25, 2010