Drobo disappears after heavy transfers

I’ve been having an issue with my 1st gen drobo recently where after copying files to or from the drobo it disconnects itself from windows. The dashboard will report “no drobo detected” but I see the drives connected to windows just with the root directories and no files underneath it. All the lights on the drobo are normal showing the 4 drives and the total usage. The drobo and data will come back if I pull the power on the drobo and reconnect it but it takes about 5-10 minutes to reset and start showing my files again.

Any ideas what is going on here? I have the drobo at home and use it remotely while at work which sucks when it disconnects as I have to physically unplug the drobo for it to come back.

I was also having this issue. I noticed when I used a USB 2.0 Ultra card (ULS Chipset) my Drobo would disconnect at least once every two days. I swiched back to the internal Intel USB2.0 ports. Then I would get disconnects only once a week.

I now have a USB 2.0 hub (Belkin) between my two Drobo (Gen1) units and my PC. I will let you know if I have disconnection issues. I have been running stress tests on my two units and it has not disconnected yet, but it’s only been two days.

Will let you know what I find.


Thanks for the info Sonny. I’m wondering if it’s just a bad USB controller on my motherboard but I didn’t have these disconnects until recently and nothing really changed other than upgrading the firmware on the drobo and a few windows updates. Definitely let me know if you encounter any more disconnects.

I’m assuming you are remoting into your Windows computer (rather than into a DroboShare). If this is the case, and the Drobo is directly attached via usb, confirm that you have firmware 1.3.5 installed. If you do not, definitely update your firmware to the latest version. If you do have 1.3.5, you will want to run Error-Checking on your Drobo volume to ensure there is no file system corruption that your Drobo might be encountering during the transfers that is causing it to crash.

Lastly, check the firmware versions on your disks to make sure that they are current and do not have any known issues. Keep us updated with your findings.

Yup the drobo is connected directly to a Windows computer via USB. No USB switches either, just directly off of one of the motherboard’s ports. The drobo is on firmware 1.3.5 but this issue started happening on the previous firmware version.

I’m running error-checking on the first drobo volume now and I’ll do the same for the second one once it finishes. I’m unsure about the firmware of the drives and actually I forget what brand drives I have in there currently. I’ll have to check that when I get home. I do know that I have 2 1TB and 2 1.5TB drives in it.

Is there a good way to go about checking the firmware of the drives? I assume I’ll need to shut down the drobo and connect each drive manually to a computer. I just want to make sure I don’t lose any data. Think I would cry for a week straight if I lost my 2TB that I have used so far.

Here’s some screenshots of the drobo dashboard while the drobo is functioning currently if it helps.

Firmware is usually listed on the top of the drive, where all the drive information is.

The error checking finished on both volumes and reported no errors which is good. I’ll check out the drives tonight when I get home. Thanks for the suggestions!

I had completely backup all data from one drobo, formated both drobos using the drobo dashboard (Latest version Drobo Dashboard and Firmware), and unit would still disconnect. I have installed a USB 2.0 hub (external) and no more disconnects w/heavy transfers! I have a Intel ICH8 USB Controller on the MotherBoard. I have put in the belkin $19 hub in between both Drobo units and my Dell Server, and no more disconnects. Anyone else tried this?


Wow, we don’t recommend hubs since this causes disconnects.

Then tell me why ALL 3 of my Drobos 1 at work on a VIA USB2.0 chipset and two at home on an Intel Chipset would always disconnect! No response to my questions to Drobo…

Just checked my server, and no disconnects at all with the USB hub…

Do you have a lot of other USB devices connected, especially ones that require power?

I’ve see weird USB behavior when there are a number of power-hungry USB devices on the bus, even when they’re all within what the USB power limits are. Not all motherboards provide equal power on all USB ports it seems…
Case in point, on the machine I’m using right now, the front USB ports don’t provide enough power to drive a 2.5-inch portable drive, while the back ones do - even though they’re all built-in header ports on the motherboard.

Now if you tell me your USB hub is bus-powered (doesn’t have a power adapter or a Y-cable), then this theory goes out the window…

You may have some kind of timing problem which you aren’t running in to with the hub because it slows down access and masks the problem.

I have a timing problem? I think its my Drobo that has a timing problem. Also my drobo didnt slow down that I can tell. in any event, if there is a timing problem, I think Data Robotics should fix it. It seems this is not just a one person issue.


One USB 2.0 hub can “offload” a request to another USB 2.0 hub.

So… is your hub self-powered, and what other USB devices do you have connected? I’m still curious about the power.

the only usb devices I have are USB Keyboard / Mouse, and two Drobos.
My Belkin is powered (with a 4.5 amp 5volt supply). However I would still argue that the drobo should stay connected. I believe the drobo has a flaw that Data Robotics wants to keep under wraps to keep a class action lawsuit from coming to their door.


Okay, so your USB hub is powered, but it doesn’t sound like there’s a lot of draw there.

I think your class action cover-up theory is a bit premature. There’s still a ton of other factors that can be an issue, and my Drobo has been connected for 48 hours right now (doing a large file copy - it’s still going to take another 24-48 hours) and I have no experienced any disconnects. Drobo is connected to NForce4 motherboard USB 2.0 root hub, and I have a keyboard, Wacom tablet, audio device, external drive, multi-card reader, external 2.5-inch drive and external DVD-ROM drive that I have all used off and on during the time the Drobo’s been connected.

I should mention, however, that the Drobo has been in constant transfer the entire time too, so your problem might possibly have to do with power-saving or Drobo sleep.

Do you have another PC that you can use for testing for a while?

Also, if your system has a Spread Spectrum or Frequency Modulation option in its BIOS, try toggling that option. Those options tend to vary the bus clocks and can cause timing mismatch problems.


@sonny486 I would recommend you open a support case so we can review a diagnostic file.

I will do so, if Data Robotics would ever respond! I will call the number listed in Jennifer footer. Also I still have not had any disconnects since I added the HUB. I do backups every night (2 of them actually).

I will say I have lost data on my Drobos since I have gotten them. The adds say completely safe data storage, but that is not the case.


O.k. I moved my Drobo to directly onto the USB of the motherboard, now I have lost all my data! (again!) This is the thrid time my Drobo has re-formatted the pack! This is so bad, this is the third time this has happened! Unbelieveable!

I really hate DROBO now!


There is something very wrong with things if you see data connected through a USB hub but on the same system you don’t see a connection without going through the hub.

After you couldn’t see your data directly-connected to the computer, what did you do?

Did you try disconnecting Drobo, powering it down, powering it back up, and restoring the “working” connection scenario (plug the hub back into the computer, the plug Drobo into the hub)?

Have you had any troubles with other USB external storage devices?

How many Drobos do you have connected currently?
If you have both connected, they’re both on their own separate power supplies, right?

I get the feeling you’re overthinking things… Drop down to the simplest possible configuration and move forward from there, documenting everything you do and see, no matter how mundane it seems.