I've had a love hate relationship with my Drobo for a long time. After two years of using it on a Linux box, I moved it over to a Windows 7 machine where it seemed to work just fine for a long time, but it was under very light usage. Mainly backups that never actually happened.

Recently I began using it for additional backup services (through CrashPlan, which is great). This means the Drobo gets a lot more usage. Also it means that something interesting happens, the Drobo can choke my system on startup. Here's what I mean:

Start computer without Drobo plugged in, CrashPlan and Drobo Dashboard services disabled: 105s Start computer with Drobo plugged in Crashplan disabled, Drobo Dashboard enabled: 250s (and 1 cpu at 100% for a very long time, drobo churning) Start computer with Drobo plugged in, CrashPlan and Drobo Dashboard disabled: 250s (1 cpu at 100% for a very long time, drobo churning) Start computer with Drobo plugged in, Crashplan and Drobo Dashboard enabled: 300s (1 cpu at 100% for a very long time, drobo churning)

If I yank the USB plug on the Drobo the CPU usage goes down to nothing very quickly. The slow startup in the fourth scenario is because CrashPlan is trying desperately to load stuff up on the H: drive before it gives up, so I've disabled it for the time being.

So here's my question: What the heck is going on when I plug the drobo in? I've fired up Process Explorer and see that the System process is hogging the CPU, specifically it's an ntoskrnl.exe/KdPollBreakIn thread that's going ape.

Is this something that's wrong with Drobo? Windows? Any idea on how to find out?

If it matters, here's tech info: Athlon 64x2 4400, 2GB RAM, Win7 Ultimate, Drobo USB (2x1TB, 2x320GB)