I used to have issues with ATTO 41/42ES HBAs seeing all the LUNs on our XSAN system (Qlogic 5600/Infortrend RAIDS). Replacing the problem client PCI card with an Apple 4Gb card eliminated the problem.
Since updating the XSAN to Lion 10.7.4/10.7.5, and using the latest available ATTO drivers/flash files for the 41/42ES - the problems 'had' disappeared.
Unfortunately, while rumming some pre-upgrade tests using a metadata controller on Mavericks 10.9.1, it appears the problem has reoccured. Its a real issue now as I have many connected clients running the ATTO cards, and updating the MDC OS may or may not make them stop seeing the various XSAN volumes.
I've tried flashing the ATTO firmware etc, but a test client machine I have here happily running on an ATTO 41ES and Lion 10.7.5 to our existing 10.7 MDC, when connected to the test 10.9 XSAN will not see some LUNS on either 10.7 or 10.9. Swap the HBA for an Apple, and hey presto - there they are. Grrrr!
Has anyone come across this issue - or better still got a fix (that does not involve buying Apple cards!) ?