2009 April « Frank’s Weblog

Using Drobo and Drobo Share with Time Machine

Recently I have bought a Drobo and a Drobo Share. One of the reasons for this purchase was to be able to easily expand disk storage capabilities and have a central location to store Time Machine backups for both my Macs.

When I had installed my Drobo and Drobo Share I soon noticed that by default Time Machine does not allow NAS systems to be used as Time Machine backup disks. After a bit of research on the net I found that it is possible but it needs a little bit of work.

This blog post details the step I performed to setup Time Machine for my Macs

1) Setup your Drobo and Drobo Share and make sure everything is in working order and you have enough free space available to store Time Machine Backup data onto your Drobo.

2) For every Mac to be backup-ed using time machine create a sparse bundle image. You can create this disk image by using Disk Utility
Creating Disk Image.png
Normally a volume size of twice the actual size of the HDD installed in your Mac should be adequate to store multiple versions of your files into the Time Machine backup. If you have enough storage in your Drobo you can make the disk image larger. After the sparse bundle has been created make sure to eject the disk image.

2) Copy the disk image to the root folder of your Drobo

3) Open a Terminal session and execute the following command on every Mac to be backup-ed by Time Machine

defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1

4) Start Time Machine and select you Drobo as Time Machine Disk. For for Time Machine to start, moste likely it will fail or just stop the prepare action as soon as it starts. If you now look at the contect of the root folder of your Drobo you will notice that one additional file is created. This file is named something like this

Atum_001debec863e.temp.sparsebundle

Atum in my case is the name of my MacBook Pro, and 001debec863e is an identifier used by Time Machine to identify the machine.

Use the first part of the name (Atum_001debec863e) to rename the temp.sparsebundle into its proper name for Time Macine. In my case that would be

Atum_001debec863e.sparsebundle.

4) As soon as Time Machine is done working you can click on the ‘Change Disk…’-button in the Time Machine preference pane and select None from the list.
Remove Time Machine Disk.png

5) You can now delete the xxx.temp.sparsebundle from your Drobo.

6) Now again you select your Drobo as a Time Machine Disk. This time there should be no errors and Time Machine will start backing up your Mac.
Time Machine working.png

I have used to following resources from macosxhints.com while figuring out how to setup Time Machine in combination with my Drobo and Drobo Share
[1] – Create a Time Machine size limit for networked disks
[2] – Set up Time Machine on a NAS in three easy steps

April 11, 2009 Posted by fmeus | Apple, Drobo, Hardware, Network, Software, Technology | | 4 Comments