Drobo5N Reboot loop when replacing drive, please help!

Drobo 5N 2 8TB drives, and 4 TB drives. Had about 5TB free space and decided to upgrade one of the 4TB HD with an 8TB hard drive. Everything was going smoothly, I took out the 4 it started blinking, I inserted the 8TB and it started it’s rebuild process. About two hours in I noticed that I could no longer access data. The Drobo was in a reboot loop. I can stop it for a bit by catching it when the power is off, disconnecting the drives, booting up until it states need a Drive, shutting it down. Plugging the drives backj and and rebooting. The data is there, it appears for a short bit, but then it goes right back to the reboot loop. I’d love to just get my data off or have it finish it’s restore process.

Please help, does anyone know how to save this disk pack?

what model 8tb disk?

It’s a Seagate ST8000AS0002

Thankfully I have a spare unit, I was able to put the Drobo into read-only mode (ctrl-shift-alt R from the dashboard with it booted with no drives). And am able to read all of the data. It will take a few days to migrate the data, but at least it’s not lost.

Why would this happen? I have replaced drives numerous times, always with a bigger drive. I had about 30% free space, more than 7TB free space and removed a 4TB for an 8TB then it began repair but then began the reboot loop.

I would like to avoid this altogether. Should a drive be removed first, let the rebuild happen, then insert a drive once it’s done?

The Seagate ST8000AS0002 is an Archive drive and is not supported by Drobo…or any NAS that I’m aware of. Internally the drive handles data much differently than a normal HDD does, and this causes problems.