So after a bit of testing, this is what I have found.
The cards are arranged like so (ports are the switch port numbers).
Port 1 - Solaris 11.1 - ConnectX-2 (SAN)
Port 2 - ESXi 5.1: ConnectX A1 (flashed)
Port 3 - ESXi 5.1: ConnectX A2 (unflashed)
Port 4 - CentOS 6.4 (OpenSM): ConnectX A2 (unflashed)
Port 5 - ESXi 5.1: ConnectX A1 (flashed)
The server on port 2 could see the targets presented by the server on port 1 but after changing the card to an A1 (suspect it was previously an A2) it cannot.
The server on port 5 has never been able to see the targets made available by the server on port 1. It is also the server where bare metal Windows was installed and I could not get the Windows SRP target working.
On investigation I happened to look at the OpenSM log files and it was reporting IB_Timeouts on port 2 (server on port 5 was turned off). The error stated there could be an issue with the mkeys on the HCA.
sm_mad_ctrl_send_err_cb: ERR 3120 Timeout while getting attribute 0x15 (PortInfo); Possible mis-set mkey?
I then changed the cards around.
Port 1 - Solaris 11.1 - ConnectX-2 (SAN)
Port 2 - ESXi 5.1: ConnectX A2 (unflashed)
Port 3 - ESXi 5.1: none
Port 4 - CentOS 6.4 (OpenSM): ConnectX A1 (flashed)
Port 5 - ESXi 5.1: ConnectX A2 (unflashed)
Now both the servers on ports 2 and 5 can see the targets prosented by the server on port 1 and there are no errors in the OpenSM logs. The fact it is running on an A1 card seems to make no difference. I suspect that if I tried to mount the targets it may well fail though.
The lesson is to make sure you get A2 or newer version cards of the MHGH28-XTC cards.
Interestingly, port 5 servers ESXi install did not see the ver A2 card after swapping out the A1 card (which it did see) and I had to remove and re-install the Mellanox vib for it to appear which is a bit of a pain. There may be an easier way to get it to 'refresh' but this seemed a fairly good bet to work so went that way.
The target appeared in the Port 5 server and more surprisingly, the datastore also appeared without needing to import it (it is also mounted on the port 2 server). Now I should have the ability to start VMs stored on that datastore on two servers (haven't tried it yet though
and trying it at the same time would probably be a bad thing
).
I also found that the ver A1 cards will not work with ESXi 5.1 passthrough even after applying the latest patch to ESXi. After doing all the passthrough, reboot, assigning to VM stuff, on booting the VM it errors and wont start. No PSOD thankfully but still not usable this way. I have not tried A2 cards but expect the same issue.
I would need to reinstall Windows SBS 2011 Ess bare metal to the server in order to try out the Windows SRP function. After so many reinstalls of Windows servers and domain leaving and rejoining I have inflicted on my Wife and kids I am fairly loath to have to go through it all again.
I may pick up another ConnectX-2 card or two as the Dell C6100 mez cards are going for around US$150 each now which is a steal as standard PCIe ConnectX-2 cards are around US$250+ on the second hand market. Cables could double the price though
.
Update: Ok well I have just nabbed a Mellanox MHQH29C-XTR ConnectX-2 for US$189 so when it arrives I think I will put that in the ML110 G7 (port 5) and see if I can get Windows Server to work with SRP. I did consider NFSoRDMA but the Windows server is the only machine that would need access to the data and has an Infiniband connection. All the other machines are desktops without Infiniband cards. I therefore believe it will be better to take the space as block storage and then share from the Windows server via GbE.
RB