Single Mac, Time Machine and Drobo

I cannot find a definitive answer to this: if I want a single Mac to back up to a Drobo S using Time Machine, and I don’t want to use the Drobo for anything else, do I need to create a partition to restrict space used by Time Machine.

What I want (and why I bought the Drobo) is for Time Machine to use all the space available, and if in future I add more capacity I want it to use that space too.

All of the opinions and speculation I’ve seen have suggested that you need to partition the drive otherwise Time Machine will ‘overflow’ and that everything needs to be erased and repartitioned when more capacity is added.

Surely there must be a better way? Has anyone actually tried just letting Time Machine fill the drive and see what happens? Does it automatically delete old backups when it runs out of space, as it’s supposed to (I’m taking about having say 2TB of available space on a 16TB volume).

If you are formatted to a 16 TB volume size and only have enough drives in there to have 5.5 TB available for data, Time machine will try to write to a 16 TB volume size. It will never see the full drobo as full. When it tries to keep writing to a full drobo it completely corrupts your data, makes the drobo inaccessible and the best thing to do is to reformat the drobo in order to get the drobo working again.

After upgrading to a DroboFS, I took my 2ndGen Drobo to work to use as a time machine. After formatting it with HFS+, I then went into Disk Utility and made two partitions. For the partition I am going to use with time machine, I gave it a smaller size than what drobo says is available. The other partition I made a Fat32 in case I ever need to put files someplace for a windows machine to read.

So there is no way to use Drobo with Time Machine that allows simple expansion? I know this is one specific scenario, but the advertising claims that it’s simply a case of adding another drive, no configuration required - yet it looks like I’m going to have to erase the drive each time I add more storage?

Time Machine will use all available space on a hard disk.

The problem with Drobo and Time Machine combined is that Drobo pretends to be a larger hard disk than it actually is.

If you format your Drobo to 16TB then Time Machine will think it has 16TB to fill - even if you only have say 2TB worth of Disk in there. So Time Machine just keeps filling and filling until the Drobo stops it (by slowing down writes) when you have almost filled your physical space.
At this point Time Machine still won’t clear off old backups because it does not think the disk is full.

There is a work-around:
I have not used it myself but looks pretty straight-forward. This is just an Applescript that sets up your Drobo for Time Machine and stores the backup in the sparse bundle image. As long as the maximum size of the sparse bundle is less than the actual capacity of your Drobo you won’t have any problems.
As you increase the space on your Drobo you can increase the space of the sparse bundle via a simple command in Terminal:

Thank you - I’ll try this. Presumably the app isn’t designed to allow resizing without using the terminal?

It looks like the App is designed just to be run Once when you set it up to create the necessarily files on the Drobo (Time Machine Config files) and according to the notes it just picks a particular size based on the size of your hard disks.

After that you would just run the apple utility from Terminal built into OS X to adjust the size of the sparse bundle.

Hi !

Time Tamer seems to work only with sparsebundle but my Time Machine (Mac OS 10.5.8) is making backupdb …

Do you now a way to force Time Machine to make sparsebundle ?

OK !

I find a way ! I’ll try to explain it with my poor english, sorry.

After 2 days of failure in trying to use Time Tamer I have found a solution.

For information I’m using an iMac G5 1,6ghz 17" with OS 10.5.8 or an iBook G4 1,33ghz 12" with same OS.

When launching Time Tamer the process goes well except that there is no sparebundle visible in the Drobo. I don’t know why. Is that a specific bug from my hardware & software ?

So, I noticed that the report “README-from-TimeTamer.txt” mentioned a name for a file that was “successfully” created but I didn’t see. I simply copy the name of this ghost file and open Disk Utility to create a sparebundle file with this name.

After setting Time Machine to backup on the Drobo the backup start as described in the read me file “Time Tamer.pdf”.

Maybe someone must check this …

Replied in your other thread.