This will help to explain.
Dashboard, Drive information reads: Warning or Healed
Do I have a bad drive?
All Drobo storage devices indicate a bad drive by displaying a blinking red light next to the suspect drive.
When a red blinking light appears next to a bay slot, remove that drive and replace it with a new one of equal or greater capacity.
There is no need to shut down your Drobo device when swapping a drive.
The back of the Drobo face-plate will show you “drive bay actions required”.
What should I do?
From the Drobo Dashboard you can also go to Status and click “Drive Information”. This will let you select a drive and check the “Health” of each drive. You will also be able to see the model, firmware and capacity of your drive.
In Drobo Dashboard > Status > Drive Information > Health, you may see something other than " Good ", you may see:
This message appears when a drive encounters block errors during an IO operation.
This does not mean your drive needs to be replaced, Drobo will blink the drive bay Red if action is required.
Another status you may see is:
This message appears when Drobo encounters a bad block on a drive. Drobo will then re-create that failed block on another part of the drive.
This does not mean your drive needs to be replaced. Drobo will blink the drive bay Red if action is required.
For a list of recommended (and non-recommended) drives, see:
Can I really use any drive in Drobo?
For Disk Eject, try the following: