Forum Discussion

Aspirant

Jan 15, 2020

Drobo Pro to RNDU6000

Hi, Just accquired a Drobo Pro DRPR1-A which is a DAS, somehow want to connect it to my ReadyNAS Ultra 6 and manage it through ReadyNAS web interface. Any suggestions and exprience with the above we...

Sandshark

Sensei

Jan 15, 2020

OK, I don't know which generation Drobo that is, but let me tell you my experience in trying that with a 5-bay Gen 3 model. This was a few years ago, so firmware updates may have changed things.

The biggest problem is that you really need their dashboard, and they have no such animal that can work on a NAS (even their own) or any Linux system. Their (IMHO really incomprehensively stupid) idea of a "virtual drive" where the reported free space is based on some theoretical max if you add enough additional drives, is impossible to work with without the dashboard. They do have a poor work-around where you can set up a special "backup partition" that has a specified max size (but only one, and never expandable, even if you add drives) so backup software will know when to start trimming based on (at least theoretical) fullness. But all partitions (including the backup one) still draw from the same pool of drive space as needed, they don't reserve it. You can maybe get by using the "backup partition" without constant access to the dashboard But you'll still need to move it to a PC or Mac with the dashboard periodically to check on things, including both fullness and SMART, since you have no direct access to them outside their dashboard..

I believe earlier generation units and earlier firmware for the Gen3 had a max partition size of 16TB, which probably works out better in the long run as long as you don't create (or at least use) more than can use the total available drive space.

If you are running OS6 on your Ultra, I think you are better off leaving the Drobo on a PC or Mac and sharing it with the NAS via DFS. One drawback to that is that the DFS share (and any other linked share/file, BTW) doesn't show up in the GUI share displays. The other, of course, being that it's going to be slower to access that way, since it uses Ethernet instead of USB3 to get to the PC/Mac. I have not tried DFS with a backup job, so don't know if there are limitations there, too.

With RAIDiator 4.2.x, I know of no way to mount an external share except via SSH.

I was fortunate enough to have a friend who, in spite of me telling him a NAS was a better option, wanted to buy my Drobo.

Joe_Goes
Aspirant
Jan 15, 2020
Thanks Sandshark for the reply, here's my thinking and correct me if Im wrong, this Drobo pro I have is a DAS unit so when I connect it to my PC it comes up as a regular USB mass storage drive so in theory my ReadyNAS Ultra should also see it as that shouldnt it? and as far as monitoring the thing, well it has indicator lights on each drive as all capacity lights on the side so I think Im good there.

I was just wondering instead of using USB is it possible to connect both using a ethernet cable where the drobo will list in the iscsi tab on ReadyNAS web interface?
- StephenB
  Guru - Experienced User
  Jan 15, 2020
  Joe_Goes wrote:
  
  I was just wondering instead of using USB is it possible to connect both using a ethernet cable where the drobo will list in the iscsi tab on ReadyNAS web interface?
  
  Connecting the Drobo via USB to the NAS might work, but you'd be limited to USB 2.0 speeds.
  
  I don't see how it would possibly work over ethernet as you are envisioning. But I don't have a Drobo, and am not understanding what iSCSI has to do with it.
- Sandshark
  Sensei
  Jan 15, 2020
  Yes, it will "just" look like a USB device that fails to properly report the free space (at least if it works like mine did).
  
  I just looked it up, and that model is both a DAS and a SAN. The ReadyNAS GUI contains no method to connect to an iSCSI SAN. The iSCSI tab is for LUNs contained on the NAS itself, not for external ones. I expect it's possible via SSH, though; but I have no idea how much use that could be.
  
  I have not dealt with a Drobo of that type, so the factors I mentioned may not exist for it, and/or there may be additional ones for iSCSI use. If it actually reserves space for the iSCSI LUN, that might get around the reported space issue. I'm sure you have to use their dashboard to create the LUN, but you could still access the dashboard via a PC or Mac connected via USB. This would differ from my solution in a few ways: it would take the PC/Mac out of the transfer, so it could be off or doing something processor intensive and not affect access. But it also means that the PC/Mac won't be able to read the files in the LUN directly, whihc may or may not concern you.