Best way to use Drobo (ver. 2) and Time Machine with multiple macs on a network?

What’s the best way to use Drobo (version 2) and Time Machine with multiple macs on a server?
[]get a Droboshare (though I hear some mixed reviews about them)
]attach to my Airport Extreme (though I’ve already had errors where even though my Drobo is HFS+ my Mac is requiring that it be Mac OS Extended Journaled)
[*]attach it to one of my computers via Firewire or USB and share with other computers on the network

Basically, I’d like the Drobo to be the target for Time Machine on all three of my Macs, if that’s possible. I’d also like to use Drobo to store other archived files, etc. - should I set up a partition?


I recommend Option 3: attach it to one of your Macs. That’s the preferred & proven solution whether you are using MacOS, Windows, Linux (hummme, Beta!) and/or VMware/Hyper-V etc.

I second @rambo - share it out from one of your Macs via AFP (this is the default). Then, just point your Time Machine on each Mac at the shared volume and you’re good to go.

Thanks for this advice. AFP should be activated by default, correct? In other words, I’m assuming I won’t need to change any settings.

A few follow-up questions.

  1. I can use my Drobo as both the location for my TM backups and as a big storage area, correct?

  2. I’m aware that if I direct TM to a network drive vs attaching it directly to my computer that there are two different backup files - backupd (when attached directly) and sparsebundle (when over a network). Are there any issues with this?

  3. Currently my Drobo drive is formatted as HFS+ though I know of and have heard of issues with this - actually, when I attached it to my Airport Extreme it basically gave me an error that I needed a disk that was Mac OS Extended (Journaled). Do you know anything about this? How should I format my Drobo drives?

  4. If I were to attach it to my Airport Extreme, are you aware of any configuration requirements or any difficulties with this?

Thanks for your very helpful thoughts

AFP is the default file sharing mechanism on the Mac so is the default if you turn on file sharing in System Preferences.

As to your questions:
1 & 2. You can share the Drobo between Time Machine and regular file storage. The only issue is disk space. Time Machine backups will grow to fit the space available, and over time may end up filling up your disk.

The method that has been recommended here a while back is to use a thing called TimeTamer (http://www.drobo.com/droboapps/downloads/index.php?id=16), which makes a disk image file called a sparsebundle, sort of like the disk image files that Mac applications typically come on. These files have two main features used here:

  1. They can be set up to have a maximum size (say 250GB)
  2. They do not allocate all the space at once, they grow as they are filled up with stuff up to the maximum size allocated at creation.
    So what you do is create one of these files, with it’s maximum size set at the size that you want to allocate to your backups. Put the file on your Drobo, then have your Macs back up to that file. You could have one such file per Mac if you like so that one Mac won’t hog all the space.

There has been some controversy around this (see http://www.drobospace.com/forums/showthread.php?tid=371). There were quite a few people who did use it successfully though, so it might be worth a go.

  1. Format your Drobo using HFS+ using Dashboard and you should be fine. Use a 16TB volume size unless you have a specific reason not to. There is no startup time penalty on the Mac for large volumes, so go straight to the biggest you can.

  2. If you do hook to an Airport Extreme you won’t be able to use Dashboard, so you will have to look at the lights on the Drobo to check it’s capacity, and you won’t get any warnings for disk failures, etc. Other than that, I’m not aware of any real downside to doing it that way.

Hope this helps.