Is it possible to connect HP Storageworks 2700 with two i/o modules ( A and B ) to two ML350 servers with P812 Smart Array controlers installed - to share the same storage space ( dual domain ). I´ve tried to check several cabling options, but with no success ( with some wrong cabling the server doesn´t have connect to 2700, or both servers connect to 2700 with different ways, so if I add partition on first server, the other server doesn´t see it )
This kind of two way (and it has to be two way, three way won't work) SAS LUN sharing is possible, others have asked this question on here before by the way. The only real problem you'll get other than possible supportability issues is that you absolutely HAVE to use a cluster-aware file system otherwise your entire filesystem will corrupt almost immediately.
Most people do this kind of block-level sharing using fibre-channel/FCoE or iSCSI by the way.