How to back up multiple Mac computers!

Yes, you can plug in an external HDD to the AEBS and let Time Machine do the rest, there is no need for partitions, as every Mac will get its own backup on the Time Machine HDD.

Time Machine FAQ

 

Actually no, this is an AEBS and not a Time Capsule. Backing up to an external drive on an AEBS is not supported by Apple (not that it can't be done, but it's tricky to set up and unreliable).

My suggestion is (1) plug the external drive into the iMac, use TC for that and (2) get Mountain Lion Server ($19.99 from the App Store) which will let you also back up your Macbooks to the iMac.

There is no need to partition the drive; you can back up multiple machines to the same volume - the only reason you might want to partition is if you want to dedicate a certain amount of space to some computers versus others (e.g. limit the space that the kids' computers can take up on TM backups while giving your computers more room for TM historic backups)

 

I used an AEBS with one USB drive attached for TM backups for years. You get into trouble if you try to attache more than one drive. A TimeMachine or the server option would be cleaner, less quirky.

I think whatever machine you chose to run sever on needs to be running at the times the other devices may be backing up or the backups will fail (any time they are on). So you pretty much have to let the server machine run 24/7.

Dunno if that's an issue for you.

 

There's an app called TimeMachineEditor that schedules TM backups for you. I use it on all my macs to do daily backups.

I believe you can set the mountain lion server on the iMac to wake on network access, but there are so many variations... with your setup I dunno for sure.

 

That will work. Actually Lion Server probably does the same thing but I'm not certain of that, I have ML.

 

I have a Logitech usb 2.0 hub plugged into my AirPort Extreme and two 1 TB drives plugged into that. I have two MacBook airs that both backup on time machine to each drive. I also have a 3tb drive plugged into the hub in the extreme which has two Mac minis both backing up to it through time machine.

So basically I have three separate hard drives plugged into the extreme and four macs backing up to the hard drives. I don't partition any drives.

 

Thanks for pointing out the existence of TimeMachineEditor! Hourly backups are a bit too much for me, so I'll look into what that utility can do.

And you can configure OS X to "wake for network access," roughly equivalent to Wake on LAN. That's a standard OS X setting (Energy Saver preference pane, maybe?). I think the machine has to be sleeping rather than off, and it doesn't always work for me, but you can test it to see if it does for you if you feel compelled to make your server sleep.

You're correct--Lion Server also has a Time Machine Server function. I'd be surprised if it's not present going back to even 10.5 Server where Time Machine itself was introduced on the client side, but I don't know. Of course, Mountain Lion server is cheaper if you don't already have Lion Server. There's no reason to worry about version compatibility--Lion Server works fine for Mountain Lion clients on Time Machine. That's my current setup at home since I'm not planning on "upgrading" my server to Mountain Lion any time soon.

 

It's asking for a username and password that has permission on the server to access the drive. I'd personally set up a different account for this purpose (on the server--check the Users and Groups section or whatever they call it now; I don't have Mountain Lion) and use that; that way, if the password gets compromised, it's different from any other accounts (e.g., your regular one) you might also have on the server.

Or, if you don't care about this situation, use a username and password that's already set up on the server. In either case, unless the message states otherwise, it's not asking for a user on your (client) computer.

Hope this helps!