changing macs perception of space on drobo

when I first purchased my Drobo I was recommended to format the drive at 2 tb. This seemed like a ton of space considering this was several years back. Now I have close to 4 tb of drive space yet my mac won’t let me copy to the drobo as it “thinks” the drobo is full.

I don’t want to completely reformat the drobo as I don’t have 2 tb worth of free space. Is there anyway to have the mac recognize that there is room on the drobo?



drobo should automatically create ADDITIONAL 2TB volumes everytime you exceed the space your operating system can see…

if you picked 2 TB as a volume size, then once you pass 2TB in REAL space on your drobo… it will create a second 2TB volumes, so you can use the additional space. once you pass 4TB in REAL space then it will create a 3rd 2TB volume, so you will be able to use your real space up to a limit of 6TB, after which it will create a 4th 2TB volume (im sure you see the pattern).

when you look in drobo dashboard does it show you a second volume? (it may be unformatted)

I am not connected through drobo dashboard. The drobo is connected to my wireless router.

Most routers and router-type devices do not support multiple volumes (or even partitions in some cases) on the attached storage. You’ll need to verify that your router supports multiple volumes/partitions on the attached storage, otherwise your Drobo is happily exposing additional volumes to support you additional space, but your router just isn’t exposing them.

exactly - i cant think of any routers which are happy with multiple volumes/

additionally… i think some routers have problems with volumes greater than 2TB, so even if you took all the data off then re-formatted drobo to show a larger volume size, then you still may not be able to use that in your current configuration

I have an airport extreme and when I go into the utility I can see two partitions.

One appears with a drop down of “Drobo External Drive”

The other “2.0 TB Trusted USB Device” doesn’t have a drop down. It seems like my router sees it, I just can’t seem to get it to mount to my desktop.

Any suggestions?

the two things which occur to me


the usb trusted device is the drobo itself - the other drobo external drive is te single partitiotn it can see


when you add more space to drobo , it only makes an additional partition, that partition still needs to be formatted, which you will need to use a computer for i suspect

the only way to actually know what is going on is to plug drobo directly into a computer and see what dashboard tells you

hmm, that does make sense. Maybe I will just connect it up and see what I can see!

well, it has taken me long enough, but I finally moved the Drobo so it is connected directly to my iMac instead of my router.

When I first booted up the iMac said the disk was unreadable. I chose to ignore and the drobo was indexed by the iMac.

Then when that was complete (some 10 hours later) I restarted and got the same message. I chose ignore again (my options are initialize, eject or ignore) and the drobo will appear on my desktop after about 5 minutes.

Drobo Dashboard doesn’t recognize a connection and when I click on the drobo I get beachballed.

I just restarted again and it didn’t even mount this time or give me an error message.

What to do?

diskwarrior is highly recommended?

? Drobo has been working perfectly on the airport extreme for several years now. Was formatted for a mac when I first got it and mostly mounts to the desktop. Is there not some step I could be missing?

Don’t have diskwarrior and not really looking to spend any money “if” there is a way I can get this drive back![hr]
also, I can see it in disk utility. Just not on my desktop. I am running repair on it right now. Will see what that does.

If you have anywhere else to put your data temporarily, it might be worth just copying the data off, reformatting to 16TB and putting your data back. Of course, you would need to verify if the Airport Extreme can deal with a 16TB volume first!

see thats the problem, I don’t have anywhere big enough to put the data. I have connected it directly to my iMac now to do away with the initial issue.

The volume repair is complete, it now says:

“updating boot support partitions for the volume as needed”. It has been doing that for a while, but still seems to be doing its thing.

When I open disk utility, the drobo is listed as a trusted USB mass storage media, with apple partitioning being the partition map scheme. Seems like everything is as it should be?[hr]
well, it has finished and I got an error message telling me that I need to reformat.

This sucks. I bought the drobo as I needed a place to keep all my data. I don’t have anywhere big enough to store this data for obvious reasons.


$100, and a good thing to have around anyway…?