16TB limit on 5N

The Drobo 5D has a 32TB maximum volume, the 5N has only 16TB.

When will the 5N have 32TB?

Does 16TB on the 5N mean that, if I have 5x6TB drives, I can create two 16TB volumes? Or is the 5N limited to 16TB? If so does one or two drive redundancy would make no difference to the available space. (3x6TB is > than 16TB.)

I think the limit is for drive, not volume. Today we max at 6 TB, with some helium HDD for enterprise can hold 8 TB. We have time before reaching the 16 TB drive limit…

With my FS as with my 5D I was limited to 16 TB max volume, but maybe a firmware released since has changed that.

Read specifications here: http://www.drobo.com/storage-products/5n/

It states: “Maximum System Capacity: 16TB”.

Please correct me if I’m wrong, but I don’t think that drobo 5N will create second volume if total available HDD capacity with redundancy is >16TB.

The specs for 5N say Maximum System Capacity 16TB, for the 5D it says 32TB.
What does this mean?
If I use 5x6TB drives in the 5N what is the available storage?
Can I configure the 5N for two volumes of 16TB using thin provisioning?
Will Drobo update the 5N to support 32TB, or is there an issue that prevents this?

Here are the numbers provided by Drobo.

Current max usable capacity:
Drobo B1200i: 32TB
Drobo 5D: 32TB
Drobo (3rd Gen): 32TB
Drobo 5N: 16TB
Drobo B800i: 32TB
Drobo B800fs: 32TB

It is not clear what Capacity means.

hi when i see capacity, i take it to be the physical hard drive capacity.
eg, if you have 4x8TB drives, that is 32TB

in actual fact, your usable space will always be less than that, depending on your SDR or DDR, and any system overheads :slight_smile:

It is still not clear what 16TB on the N, and 32TB on the D mean in practice.
What happens if I have 5x6TB drives? For both single and two drive failure it would be more than 16TB available space on the D.
Does it mean that the the maximum volume is 16TB on the N?
Can the N be configured with two volumes both less than 16TB? Or does it mean that the available space would be limited to 16TB, the additional space is not available for use?
Is this a firmware issue such that the N will be upgraded to 32TB.

I believe it DOES refer to max available space on the device.

I don’t get why the 5D has double what the 5N does atm… At this rate I’ll out-grow my 5-n by mid-spring!

from what i remember, the 5n’s were considerably cheaper then the 5ds… maybe this was also a contributing factor?

It’s the ‘deep, dark secret’ that Drobo is unwilling to address.

BeyondRAID does not support a single volume larger than 16TB.

It’s going to be their downfall and I can see no way to address it without breaking backwards compatibility.

They will announce a “BeyondRAID 2” or “BeyondRAID+” that supports single volumes in excess of 16TB, but you must reformat to enable it.

It’s a deal-breaker for me and the reason I have held off on swapping to 6TB drives in my 5D.

I don’t think this is a computing power or “cheap components” issue. I run transmission as a drobo-app with a load that would cause the app to become unresponsive on my macbook pro, and it keeps on trucking.

This doesn’t explain the 5D/5N split. They could have the 5N just make a second volume like the 5d

I’m beginning to suspect someone on the hardware end did something stupid like embed the 16T value into a chip somewhere, though I have absolutely no substantial data for this beyond the fact the 5N is the only modern device from Drobo not to receive the capacity bump…

I currently have 16TB overall capacity installed in my Drobo 5N. Does this mean I can not add any more capacity to my 5N? …or does it mean I can’t have more than 16TB available for actual data?

The latter seems comprehensible since 5x4TB - 4TB redundancy would result in 16TB usable for data.

With dual drive redundancy enabled…there would be another 4TB worth of drive capacity that could be installed when/if larger drives are eventually supported.

I did a quick online search and I actually found an offer for a 20TB Drobo 5N.

Edit: Perhaps this is one of the reasons the official support of drives >4TB is taking so long. With 5TB / 6TB drives these ‘maximum capacity’ specs are easily exceeded on the 8 bay Drobos and the 5N.
Edit 2: Hmmm. How does Drobo solve this issue when using a b1200i with 12x4TB drives? I have seen offers for this configuration.

Don’t mistake 16TB per device limit with the 16TB per volume limit.

The 5N can only hold 16TB of disks total.

The 5D and newer can hold and address more than 16TB of drives, but is still limited to 16TB per volume.

The 16TB in the 5N is most likely a firmware issue.

The 16TB per volume is a BeyondRAID limit.

As I wrote: There are companies offering kits of 20TB and a Drobo 5N.
Which indicates that your statement might be incorrect and the 16TB might be the maximum overall available space for data excluding drives for redundancy.

I just got off the phone with Drobo (Connected Data).

Current limit on single volume size for BeyondRAID is 16TB.

There is a firmware update coming that will increase the single volume size. She wouldn’t tell me how much bigger it would be. Also couldn’t tell me if it would require a reformat.

It will come 1st to ‘business class’ devices and then to 5-bay. Still uncertain about 4-bay (Gen3).

I contacted a local dealer that offers the Drobo 5N bundled with 5x6TB drives.
They got in touch with Drobo Inc. and stated that the Drobo 5N currently supports 20TB storage and there will be an update for larger capacities. (Sadly no indicator when this will happen.)

So the stated “16TB capacity” limit is apparently without the one or two drives used for redundancy.

I now have >16TB total and everything behaves as expected. The current limit for the 5N seems to be 3x6TB + 2x5TB with dual drive redundancy turned on.

20TB with redundancy and 16TB without doesn’t totally make sense either. If you had 5x6GB drives would expect to have 26GB total (16GB actual + 2 drive redundancy). If you had 5x5GB drives you would expect to have 15GB actual and 25GB total with 2 drive redundancy.

It’s good to hear that they intend to address this limitation. However, it has been over half a year since you posted this information. I wonder if anything has changed since then?

The worse case scenario would be if they decided to EOL the 5N and replace it with a newer model that doesn’t have this limitation. Once the 5N is given “legacy” status, I highly doubt we will see any fix.

Just got confirmation from Justin Winkler from Drobo that they do NOT have any plans to increase the capacity of the Drobo 5N.

Hello Elai72,
The development team is currently looking ‘to’ support greater than 16TB on the Drobo 5N, this is being reviewed - as soon as we more information we will post an update to KB: