Well every release of OS X seems to break our trusty old Drobo Pro. The things that really don't work:
- iSCSI initiator. The one they use needs an old Java 6 and is pretty flaky, but there are not complaints like the Firewire and USB. I've had lots of prior issues with this as having two Ethernets running (one for the network and one for the Drobo Pro on Lion didn't work). But given the reliability problems of Fireware and USB (see below), it seems like the best choice right now
- Firewire 800 hangs and locks machine. This is slow on boot and locks up the machine. This is the one that worked fine on Mountain Lion, but doesn't work well here.
- USB drops out. So it seems likes the options are to go back to Mountain Lion or try it with the slow USB 2.0 connection. Unfortunately, this seems to cause the Drobo to go to sleep and for the volumes to disappear.
- Run Mountain Lion. OK, I have this in reserve, get an old laptop and run Mountain Lion and FireWire which did seem to work or connect it to the Synology box.
So much for "old" hardware (4 years old) working with things. Or it could be a hardware failure which Apple lets you test for with their hardware diagnostics (hold D during a reboot). See https://support.apple.com/kb/ht1509.
I rebuilt Mac OS X Mavericks yesterday because I was getting so many hangs at Finder. So it might be the hardware. I need to run the Apple Hardware diagnostic as previously this machine would "bong" and then hang, so it could also be the hard drive.
So basically, there doesn't seem to be a reliable way to get this to work.