Question on Drobo - extending partitions

[danny_w]

I was searching on Drobo and Time machine and found this thread. I am a bit confused on Drobo and Time machine.

Not sure how to word this so i will try my best. Here is my scenario. I plan on getting a Mac Pro I want to load up 2 additional hard drives along with my normal boot drive. The additional drives will store all my dvds that are handbraked for apple tv. I want a drobo loaded with a couple of hard drives as a time machine. I want the drobo time machine to back up everything on all the drives on the Mac Pro.

All I want is my Drobo to do is backup with time machine, no extra partitions for anything else. Please explain to me how i can use a drobo to do this. When i first set up do i set the partition to 16TB (assuming my TM will grow over time)? When really I would only have (2) 1.5 TB disk in the Drobo. So if the partition is set to 16TB does time machine think there will be 16TB when i will only have 1.5TB to start? When I start adding additional drives into the drobo with the 16TB drive partition i set earlier will TM just grow into more space from 1.5 to 2 to 3TB etc...?

So basically can Drobo Time machine backup everything on my mac pro and grow on the fly as more data is filled on the Mac Pro?

Thanks hopefully that made some sense.

That's a very good question and one that I can't answer for sure. I have a Drobo but I don't currently use it for TM; I have TM set to use a 750GB WD MyBook connected to my AEBS. I would be worried that TM would "see" the Drobo as a 16TB disk, and would overflow the disk without warning and without limiting itself, leading to a TM failure. I know that DataRobotics has a utility available to limit TM backups by creating a sparse-bundle in TM format except for adding a limit (I think by default TM sparse-bundles are not limited). For example, you would initially have about 1.5TB available with 2 1.5TB drives; you could limit TM to 750GB for example using this technique, and when TM got to the limit it would start deleting older backups. However, I don't know if you could change this limit when you add more disks.

 

[akm3]

When using a Drobo as a Time Machine backup, you should use a DroboApp that lets you set the maximum size Time Machine will use and/or there are some Mac Apps / Terminal Hacks that accomplish the same thing.

 

[danny_w]

When using a Drobo as a Time Machine backup, you should use a DroboApp that lets you set the maximum size Time Machine will use and/or there are some Mac Apps / Terminal Hacks that accomplish the same thing.

That is the app that I was referring to above.

 

[bestthereis27]

When using a Drobo as a Time Machine backup, you should use a DroboApp that lets you set the maximum size Time Machine will use and/or there are some Mac Apps / Terminal Hacks that accomplish the same thing.

So the app lets me put a maximum GB or TB on the partition. So once it hits the Max it will delete older backups and continue doing its thing like normal. So lets say set the limit 1 TB using (2) 1.5TB disk, thats all well and good but lets say i have more to back up and i want to throw in another 1.5 TB disk in drobo.

How do i increase that 1TB maximum limit while keeping the old backups? Do i need to format the entire drobo again and up the limit from 1TB to 2TB? Then do a full backup from scratch? I am hoping that App will allow me to grow the Max when adding new drives.

 

[danny_w]

So the app lets me put a maximum GB or TB on the partition. So once it hits the Max it will delete older backups and continue doing its thing like normal. So lets say set the limit 1 TB using (2) 1.5TB disk, thats all well and good but lets say i have more to back up and i want to throw in another 1.5 TB disk in drobo.

How do i increase that 1TB maximum limit while keeping the old backups? Do i need to format the entire drobo again and up the limit from 1TB to 2TB? Then do a full backup from scratch? I am hoping that App will allow me to grow the Max when adding new drives.

Has anybody tried growing a sparse-bundle created with this app? This is the same question that I was wondering about in my post above. I would also like to know the answer.

 

[bernhardw]

Hello,

I'm too thinking about buying a Drobo, but in my opinion the question regarding the partitions is unanswered.

1.) Lets say I have 4x1TB disks in my drobo, this will get me 3TB usable space
2.) Lets say I configured Drobo to show this space as a 16TB disk

This is only the raw space, now I want to add partitions and format them with different Filesystems.

Now I create the following partitions:

(A) - 2TB - (j)HFS+
(B) - 900GB - NTFS
(C) - 100GB - FAT32

After a while I want to add space, so I upgrade the disks to provide 5TB raw space.

What to do then? How do I get the extra 2TB to either (A) or (B)?
OK, maybe I could resize (C), with FAT32 limits of course, but thats it.

I just don't get it.

Thanks in advance,
Bernhard

 

[stomer]

Hello,

I'm too thinking about buying a Drobo, but in my opinion the question regarding the partitions is unanswered.

1.) Lets say I have 4x1TB disks in my drobo, this will get me 3TB usable space
2.) Lets say I configured Drobo to show this space as a 16TB disk

This is only the raw space, now I want to add partitions and format them with different Filesystems.

Now I create the following partitions:

(A) - 2TB - (j)HFS+
(B) - 900GB - NTFS
(C) - 100GB - FAT32

After a while I want to add space, so I upgrade the disks to provide 5TB raw space.

What to do then? How do I get the extra 2TB to either (A) or (B)?
OK, maybe I could resize (C), with FAT32 limits of course, but thats it.

The only device that knows that you really only have 3TB of actual storage space is the Drobo. Windows and Mac will both see a 16TB storage device, so if you create the partitions as you've described, you'll be left with 13TB of unpartitioned space.

Nothing will happen if you increase the actual storage space, because the logical storage space will still be 16TB. You'll still have a 13TB of free space. If you want to use it, you'll have to partition it.

Remember, you cannot resize partitions once you've created them (unless you're prepared to lose data). So you may as well come up with a partition scheme that spans the full 16TB. If you start running of space, your Drobo will begin to slow down and you'll just have to free up some space or increase your actual storage.