I have have an 800fs that previously had 5x 3TB drives, with 3 bays empty. Drobo is set to single disk redundancy.
Last week, I removed one of the 3TB drives and replaced it with a 2TB drive. After quite a bit of time, the array finished rebuilding, and the device was usable again, as expected.
Today, I removed another 3TB drive and replaced it with a 2TB drive as well, leaving a configuration of 3x 3TB drives and 2x 2TB drives, with 3 bays empty. Instead of rebuilding the array again, as expected, the Drobo is instead asking me to insert a new drive into bay 6 which has always been empty. It also displays a warning that the Drobo cannot protect against disk failure until I have provided at least 2 drives for single disk redundancy.
Why is it doing this? I understand that by replacing my drives with smaller ones, I am reducing the amount of usable space - I want the array to simply rebuild again, reducing its size accordingly to work with the existing disk configuration. I do not want to add another drive to the device right now.
What are my options?