Cannot mount Drobo under Ubuntu - non-journaled HFS+ volume


My problem is the following: I cannot mount my Drobo under Ubuntu 10.04 LTS (anymore). I’m using non-journaled HFS+. The Drobo contains three 2-TB drives. I formatted it from my MacBook Pro. I clearly remember being able to mount the Drobo under Ubuntu a few months ago. I was able to read and write files without any problem. At that time, the volume was almost empty. Now, it’s almost full. The error I get is the following:

"Unable to mount 18 TB Filesystem

Error mounting: mount: wrong fs type, bad option, bad superblock on /dev/sdb2,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so"

I would swear it appeared as a 16-TB volume a few months ago. Could it be the reason why Ubuntu doesn’t want to mount it?

Any solution?

Screenshots from Disk Utility (Mac OS):

Screenshot from Drobo Dashboard (Mac OS):

Screenshot from the error message (Ubuntu):

Screenshots from Disk Utility (Ubuntu):


Connect it to a Mac and run a “Repair Disk” from Disk Utility. Once you have corrected any errors you can try again on Ubuntu.

As you can see on one of the screenshots I included in my message, the volume is perfectly fine:

I’ve clicked on “Repair Disk” anyway, but nothing needed to be fixed. The files can be read and written without any problem on the MacBook Pro. I have a lot of ZIP, RAR, and FLAC files on the Drobo, so I’ve been able to check their integrity.

Does Ubuntu support volumes larger than 16 TB?


@Jennifer, he’s using non-journalled HFS+, not EXT…

Sorry, missed that part.

So, any idea?

Should I post this message on an Ubuntu forum instead?

Should I try and contact the people responsible for the HFS+ support on Linux?

Should I open a support ticket?

Unfortunately tech support will not be able to help you with Linux. We will have you connect the drobo to a mac or pc.

I would recommend posting on Ubuntu forums.

Ok, I will try.

Of course, if anybody here has any experience using an HFS+ volume under Ubuntu (16 TB or more), I’m interested!


One question that you can maybe answer: is it normal that the HFS+ volume (or any volume, for that matter) on my Drobo appears as a 18-TB volume? I thought 16 TB was the maximum supported size for a volume on a Drobo?

Mac OS X Snow Leopard will report it as 17.59TB in the Finder as it changed its reporting to be in line with that used by hard disk manufacturers. If you look in Disk Utility you can see the size in bytes - which if you do the math works out to 16TiB.
I think Ubuntu used this method in at least one release (not sure if they stuck with it).

I’ve found an answer to my question:

Apparently, HFS+ volumes larger than 2 TB are not supported anymore (I was pretty sure it worked with a previous version of Ubuntu I tested a few months ago).

Hope it will be fixed soon…