Hardware / 

18 Jan 2022

Updates on the Dumpster Drobo b800fs

Now that the “Dumpster Drobo” (an old Drobo b800fs) isn’t making noises like an angry garbage disposal whenever it’s turned on, I figured it was time to actually play with it. A NAS without any data on it isn’t very fun.

So I logged onto it from my desktop Mac via SMB/CIFS, and started copying files to it. And that’s when I realized that the unit might have been left next to a dumpster behind an office building for a reason. It was horrendously slow.

As it turns out, the Drobo b800fs has something of a reputation for being very slow, even among Drobo models – which, as a class, are not known for speed.

Even after enabling Jumbo Frames (which increases the MTU size to 9000 bytes), the best throughput I could get – no matter if I connected via SMB/CIFS or AFP – was about 30MB/s write, and 35MB/s read.

This is pretty dismal from an 8-bay NAS running on Gigabit Ethernet, and I’m at a bit of a loss to explain why. The b800fs hardware doesn’t look terrible. Although Drobo’s official spec sheets don’t get into details, it appears that the b800fs hardware is very similar to the Drobo Pro FS, which was reverse engineered and described in this blog post by Daniel Parnell. And it comes with a FW800 port!

Looking at my unit compared to the photos of Parnell’s Pro FS (attached to the blog post linked earlier), one of the only differences I can see is the lack of a FireWire port right next to an empty BGA IC site on mine, which I assume is where the FireWire 800 controller would be populated on a Pro. (This makes sense, as FireWire controllers were notoriously expensive due to licensing fees, one of the reasons the connection never took off like USB did.)

This makes me suspect strongly that, if I wanted to reopen the case and start poking around, it would probably be possible to connect via serial console to either the Linux or VxWorks operating systems running on the device. And if I can connect to the embedded OS, maybe I can figure out why the SMB transfer rates are so darn slow. Who knows, maybe I can even get rsync working on it; that would instantly make it a whole lot more useful, even at only 35MB/s. It’s a bit of a long shot, and I suspect the Dumpster Drobo will end up back at the electronics recycler eventually, but it seems worth playing with before I give up and toss it.

First, however, it makes sense to check the USB port on the back of the b800fs, and see what if anything I can do through it. Hopefully it’s useful for something; it’d be a bit weird to have removed the FireWire port and controller, but left a USB 2.0 port on the motherboard without allowing it to be used to communicate with the operating system, access the firmware partition, or some other function.