I’ve been on this issue for a while with Drobo’s Tier 3 support, and a handful of guys at Apple. I finally checked out these forums today, and was able to piece everything together.
Drobo Pro was “disconnecting” from my brand new Macbook Pro while doing simple Log&Transfer work in Final Cut Pro. This is a process that I’ve done countless times on my C2D iMac and Core Duo Macbook Pro. When connected via iSCSI, L&T would completely freeze after a few seconds of working. In turn, finder would freeze and no data from my Drobo Pro would be accessible until I did a hard reboot on the computer. All of this happened regardless of the state of the AirPort, network settings, Font Book settings or PRAM zappage. It felt exactly like a full-on disconnection, but without any acknowledgement from OSX about the disconnect.
The fact that my Drobo works perfectly with the other two Macs convinced me that it was a hardware issue on the MBP. According to Apple, there was no difference with the Ethernet architecture between this MBP and any other Mac, and according to Drobo, there was no reason that the iSCSI initiator would do anything differently. As it turns out, there is something about the new Macbook Pros that everybody overlooked:
By default, the 2011 Macbook Pros boot into 64 bit mode
After reading up on the symptoms in the “Drobo iSCSI DOES NOT WORK ON 64-bit MAC7” threads, that turns out to be the exact case. Drobo’s speed into my mac was at 1MB/s or less. It wasn’t a total disconnection, but a drought of data.
I tried the fix mentioned by DrDavid, but it didn’t work. Has anybody found any other workarounds, or do I just need to sit on my hands and wait? More importantly, has anybody with a 2011 Macbook Pro on iSCSI not run into this issue?