I’ve noticed that quite a lot of people are having serious performance issues with the new Mac OS X Lion and the 1.2 FS firmware.
TL;DR: Try the steps presented in this page: http://www.alexanderwilde.com/2011/04/os-x-lion-connection-error-with-afp-and-workaround/
My investigation so far indicates that the problem is three fold: 1) The DroboFS has a quite slow CPU, 2) Apple changed the authentication mechanism used in the TimeMachine which now uses a much more CPU-intensive algorithm, and 3) The latest version of the software used by DRI to provide TimeMachine functionality (netatalk) has some serious performance bugs.
As you can see, this is the worst kind of bug there is, since several parties are at fault:
- If the Drobo CPU wasn’t so slow, this wouldn’t be so much of a problem
- Apple thinks that the previous authentication mechanism is not secure enough, so they disabled it by default
- The guys at netatalk went to the dark side, and decided to close the source of netatalk for this release (quite the scummy move, IMHO, but that is a different discussion) thus making it impossible for the community to try to fix the bugs
My advice to Lion owners that still want to have TimeMachine functionality on their Drobo is to go back to the previous FS firmware (thus getting rid of the new, buggy, netatalk) and then enable the old authentication mechanism on their Lion machines as indicated on the link above.
On a side note: I find it funny that the previous authentication mechanism is insecure enough to warrant a sudden change in Lion, but not insecure enough to warrant a patch to the previous releases of the OS… stay classy Apple.