Drobo

B810N Copying Large files fail

Hi All. Hope someone here can point me in the right direction. Latest firmware on my B810n - before anyone asks :-).

I have 2x 400GB SSDs for tiering and then 6x 10TB for capacity in my Drobo. No dual disk redundancy - just plain standard. Client is Windows.

My problem is, whenever I copy single large files (30GB per file) to my Drobo, the copy starts at 112 MBps (which is right since I have 1Gbps dedicated), then the spindle disks start to go crazy and the speed drops to Zero - after which the copy times out/fails. When the speed drops and the drives go crazy, I can see from the Drobo app that the device is TIERING sience the TIERING IOPS are 200+.

So what it looks like is that the full file size is reserved on the Drobo, which automatically kicks off a tiering process, which pauses any new writes to the device. READS work throughout.

Yes - I can remove the tiering drives and that solves the issue, but that is the reason I bough the B810n - to speed up writes but more importantly low latency writes. I understand that in the game of NAS devices the Drobo 810n is small, but I would expect a $1000 NAS to easily handle a 30GB file write without issues.

Help/thoughts would be appreciated :-).