How to Password Protect a Drobo (MAC)


I’ve looked into trucrypt etc but didn’t want to mess around with any formatting.
Making an encrypted image of 4TB is not practical (won’t go that high anyway)

Any ideas?

Thanks a lot!

What exactly are you looking to do? Do you want the Drobo itself to be encrypted, or just prevent access to it while it is mounted on the computer?

Hey and thanks for the reply.

I’d like to prevent access when it’s mounted onto another computer. Is there a solution?

Are you on a droboshare or just a drobo?

You can’t really use full disk encryption like TrueCrypt due to the thin provisioning. I found a site the other day that used something called EncFS which encrypts file by file instead of the whole disk. This solution was very comand line heavy, involving MacPorts and Fuse. If you are comfortable in that world this might work for you. I’m not at my usual computer so I don’t have the link to hand, I’ll post it later.

Can I encrypt the data I store on a Drobo storage device?

Yes – provided that you create a fixed-size container for the encrypted data.

One easy way to do this is to create an encrypted disk image using Disk Utility on OS X or using Windows Explorer’s file attribute option in Windows (not available on Windows XP Home Edition). Many third-party applications are also available for creating encrypted files, folders, and disk images.

Be sure not to use a full-disk-size option when encrypting your data: the Drobo device will confuse many forms of Full Disk Encryption. As a Full Disk Encryption tool tries to encrypt the whole disk (or “full disk”), it never reaches the end on the Drobo storage device. This infinite task is due to the fact that a Drobo storage device is essentially a limitless hard drive that creates virtual volumes larger than the actual disk space available (called “thin provisioning”).


Thanks for the replies.

You can’t encrypt a whole 4TB drive as it’s too large. No droboshare either. It’s such a shame dashboard doesn’t have this feature.

Spiney - thanks but that sounds quite a procedure to do, especially if you have loads of files on the drobo.

Any other methods? My old maxtor had a password feature, surely this can be done? :slight_smile:

If you are running Mac then use a Sparse Bundle Disk Image.

This has the option for either 128 or 256bit encryption. Because it is a sparse image you can create a 16TB sparse bundle but it only fills out on the disk as you add files to it.

This is perfect match for the Drobo which presents itself as a 16TB disk.

I don’t think the you can create a 16TB sparse bundle image. You could do a few but it becomes messy… I know they self expand but reading around it doesn’t contract if you don’t fill up the sparse image. Interesting suggestion - thanks for the thought.

Maybe a suggestion to the drobo team would be to include some simple password protect feature - it’s hard to believe
such a simple problem doesn’t have a solution - lots of people buy drobos for backups and a little security should be a given in the software.

BTW, thanks for setting me up Jennifer! I’m now activated!

My old Windows version of True Crypt can use a file as container for an encrypted file system. It works perfectly. The file is fixed at the size it got when created so you can not use thin provisioning. It is still nice if you just want to have a limited number of files encrypted.

Sure you can - just use Disk Utility, select Sparse Bundle, then custom size. You can specify 16TB no problems. The initial image is about 2GB in size and then expands as you add files.

If the sparse bundle is wasting lots of space after you delete files then you can compact it to reclaim the wasted space: http://ep1curus.wordpress.com/2008/12/16/resize-a-sparse-bundle-image-using-terminal/

ajspencer - you are the man with the plan. Thanks for the link! Possibly a workaround until drobo include this feature in the next version of dashboard…ahem! ;D

I’ll post the EncFS link here for the sake of completeness for any who are interested: http://techieblurbs.blogspot.com/2010/02/howto-replace-filevault-with-encfs.html

  1. I haven’t tried this
  2. It might not work on Snow Leopard at the moment
  3. I haven’t tried this
  4. This encrypts at a single file level, so if you want to back up your Drobo somewhere using Carbonite, rsync, Mozy, etc., this might work for you better than the sparsebundle solution
  5. Did I say I haven’t tried this
  6. It uses Fuse (Filesystems in User Space), so the concept should be familiar to anyone who has used sshfs, MacFusion or the like
  7. I really haven’t tried this

Surely the guy can just add the drobo to his shared list on the mac its connected to and turn everyone else to ‘write only’ meaning they have no access to files on the drobo unless they know the name and password of the host mac.

I have not tried this but its seems slightly less difficult than other suggestions.

I read from this quote that he wanted to password-lock the disk itself for if it was out of his possession and got plugged into another computer. Setting a sharing password doesn’t do that.

I’ve been using TrueCrypt, albeit on Vista/64, with Drobo v2 and “full-disk” encryption for about half a year. My experiences are:

  1. There are no problems using “full disk encryption”. Just remember you must specify an encrypted drive size smaller than your actual physical drive size. 4 x 1.5TB would for example give you a full sized TrueCrypt volume of 4TB.
  2. The difference in performance between an unencrypted disk and an encrypted disk in only about 10-15% depending on the type of disk operation. This was measured using AES. More secure encryption algorithm’s gives a higher performance penalty.
  3. It’s absolutely ESSENTIAL to backup the encrypted drives “volume header” using the TrueCrypt utility. I’ve lost the header two times during power failures, but was able to restore it the second time.
  4. You might find that the “Storage Capacity” inside Drobo Dashboard and/or the front of the Drobo are no longer showing correctly once you have mounted the encrypted volume.

just fyi, i recently tried it on my v1 drobo… made a 300GB fixed-size container on one of my 2TB volumes.
took around 6-8 hours to make, approx 13.2MB sustained to create.

havent tried putting anything on it yet but im sure you could creat something similar, and to simply create something larger say 3x1tb on it.
Dochris do you have any numbers/stats regarding your usage?

Paul - thanks for this update brave drobo warrior. Haven’t got round to creating my 6tb container yet but will do soon…

Please keep us updated! :slight_smile:


hi musio heres some info for you:

been using it for a few months now, and no issues so far.
even had some powerlosses (or mistakes where ive unplugged the wrong drobos power cable LOL) and all still working fine. (again, i still have everything backed up on another drobo before trying things out like this, but no issues so far) :slight_smile:

even just running a read only chkdsk on a volume currently, 50% complete with no issues so far - if that changes, i’ll post back :slight_smile:

FYI, you can reclaim space from a sparse image using the terminal with the following command:
hdiutil compact /some_path/your.sparseimage

Put that in your cron and run it once per day/week to automate the process.