And here’s why: on Aug 2014 I bought a 5D which lasted two years before the chassis died. On Oct 2016 Drobo sent me a replacement 5D which lasted four years, dying on Sep 25, 2020 (I’m pretty sure it’s the chassis again as the power supply is displaying a steady green light and the 5D is indicating there are no drives present (there are 5 10TB drives installed)). Basically, I’m done with Drobo and have ordered a QNAP TL-D800C JBOD chassis to replace the 5D.
As an aside, thank god I have a recent backup of the 5D I can use to restore to the QNAP when it arrives. From experience, having a two disk redundant setup on a 5D doesn’t buy you much recovery when the chassis dies. I have to wonder what the MTBF is for the 5D (Drobo isn’t telling, AFAIK).