I didn't think SSD tiering would cause issues but would give false benchmarks due to the caching. I guess it doesn't matter much since all of my tests have been with the caching on so as long as I stay consistent. Are you using 2 separate switches or just 1? Also, you mentioned it was a Cisco, could you please run the following and tell me if you have any OutDiscards on your iSCSI interfaces either Host or Drobo?
show interfaces counters errors
You could also run this command:
show interface "interface"
Look at the following columns:
Total Output Drops
Pause Input
Pause Output
I'm sure you are busy so I totally understand if you can't. I'm just curious. Thanks