My Drobo model DR04DD10 running firmware 1.4.2 [1.254.50341] is throwing this error: "Too many hard drives have been removed. Please re-insert the removed hard drives. "
I have 3-2TB and 1-3TB drive inserted.
Currently, all four drive indicator lights are solid red and no blue lights at the bottom.
Usually “Too many hard drives removed …” message means multiple drives failure.
I believe your Drobo is the older model 4-bays, with FW800 and USB 2.0. And it supports Single Disk Redundancy.
This means that the Drobo might have suffered from more than 1 drive failure that is why “Too many hard drives removed…” example dual drives failure in this case.
At this stage, you can try to do this as ensure that is not a case of loose connection of drives that causes a false alarm.
Power OFF the Drobo unit. Make sure it is totally no power.
Remove all the drives from the slots and re-seat all the drives back and make sure it seat securely.
Once you have done that, power ON the Drobo again and see if the same message appears and if ALL bays are RED.
Do NOT remove drives while the Drobo is Powered ON.
If after re-seating all drives into the slots and problem still persists. It really likely a case of multiple drives failure.
At such, it important to identify which are the fault drives and maybe cloning of those fault drives is required.
As Don indicated “too many hard drives removed” indicates one of drives is not seated properly or a drive failed during the data protection mode. If the latter, this means a drive needs to be block level cloned in order for the data protection mode to continue. At this point you may want to consider doing a block level clone of all your drives and work off of the cloned drives in order to gain access to your data.